New for 2025, the American Physical Society (APS) is combining its March Meeting and April Meeting into a joint event known as the APS Global Physics Summit. The largest physics research conference in the world, the Global Physics Summit brings together 14,000 attendees across all disciplines of physics. The meeting takes place in Anaheim, California (as well as virtually) from 16 to 21 March.
Uniting all disciplines of physics in one joint event reflects the increasingly interdisciplinary nature of scientific research and enables everybody to participate in any session. The meeting includes cross-disciplinary sessions and collaborative events, where attendees can meet to connect with others, discuss new ideas and discover groundbreaking physics research.
The meeting will take place in three adjacent venues. The Anaheim Convention Center will host March Meeting sessions, while the April Meeting sessions will be held at the Anaheim Marriott. The Hilton Anaheim will host SPLASHY (soft, polymeric, living, active, statistical, heterogenous and yielding) matter and medical physics sessions. Cross-disciplinary sessions and networking events will take place at all sites and in the connecting outdoor plaza.
With programming aligned with the 2025 International Year of Quantum Science and Technology, the meeting also celebrates all things quantum with a dedicated Quantum Festival. Designed to “inspire and educate”, the festival incorporates events at the intersection of art, science and fun – with multimedia performances, science demonstrations, circus performers, and talks by Nobel laureates and a NASA astronaut.
Finally, there’s the exhibit hall, where more than 200 exhibitors will showcase products and services for the physics community. Here, delegates can also attend poster sessions, a career fair and a graduate school fair. Read on to find out about some of the innovative product offerings on show at the technical exhibition.
Precision motion drives innovative instruments for physics applications
For over 25 years Mad City Labs has provided precision instrumentation for research and industry, including nanopositioning systems, micropositioners, microscope stages and platforms, single-molecule microscopes and atomic force microscopes (AFMs).
This product portfolio, coupled with the company’s expertise in custom design and manufacturing, enables Mad City Labs to provide solutions for nanoscale motion for diverse applications such as astronomy, biophysics, materials science, photonics and quantum sensing.
Mad City Labs’ piezo nanopositioners feature the company’s proprietary PicoQ sensors, which provide ultralow noise and excellent stability to yield sub-nanometre resolution and motion control down to the single picometre level. The performance of the nanopositioners is central to the company’s instrumentation solutions, as well as the diverse applications that it can serve.
Within the scanning probe microscopy solutions, the nanopositioning systems provide true decoupled motion with virtually undetectable out-of-plane movement, while their precision and stability yields high positioning performance and control. Uniquely, Mad City Labs offers both optical deflection AFMs and resonant probe AFM models.
Product portfolio Mad City Labs provides precision instrumentation for applications ranging from astronomy and biophysics, to materials science, photonics and quantum sensing. (Courtesy: Mad City Labs)
The MadAFM is a sample scanning AFM in a compact, tabletop design. Designed for simple user-led installation, the MadAFM is a multimodal optical deflection AFM and includes software. The resonant probe AFM products include the AFM controllers MadPLL and QS-PLL, which enable users to build their own flexibly configured AFMs using Mad City Labs micro- and nanopositioners. All AFM instruments are ideal for material characterization, but resonant probe AFMs are uniquely well suited for quantum sensing and nano-magnetometry applications.
Stop by the Mad City Labs booth and ask about the new do-it-yourself quantum scanning microscope based on the company’s AFM products.
Mad City Labs also offers standalone micropositioning products such as optical microscope stages, compact positioners and the Mad-Deck XYZ stage platform. These products employ proprietary intelligent control to optimize stability and precision. These micropositioning products are compatible with the high-resolution nanopositioning systems, enabling motion control across micro–picometre length scales.
The new MMP-UHV50 micropositioning system offers 50 mm travel with 190 nm step size and maximum vertical payload of 2 kg, and is constructed entirely from UHV-compatible materials and carefully designed to eliminate sources of virtual leaks. Uniquely, the MMP-UHV50 incorporates a zero power feature when not in motion to minimize heating and drift. Safety features include limit switches and overheat protection, a critical item when operating in vacuum environments.
For advanced microscopy techniques for biophysics, the RM21 single-molecule microscope, featuring the unique MicroMirror TIRF system, offers multicolour total internal-reflection fluorescence microscopy with an excellent signal-to-noise ratio and efficient data collection, along with an array of options to support multiple single-molecule techniques. Finally, new motorized micromirrors enable easier alignment and stored setpoints.
Visit Mad City Labs at the APS Global Summit, at booth #401
New lasers target quantum, Raman spectroscopy and life sciences
HÜBNER Photonics, manufacturer of high-performance lasers for advanced imaging, detection and analysis, is highlighting a large range of exciting new laser products at this year’s APS event. With these new lasers, the company responds to market trends specifically within the areas of quantum research and Raman spectroscopy, as well as fluorescence imaging and analysis for life sciences.
Dedicated to the quantum research field, a new series of CW ultralow-noise single-frequency fibre amplifier products – the Ampheia Series lasers – offer output powers of up to 50 W at 1064 nm and 5 W at 532 nm, with an industry-leading low relative intensity noise. The Ampheia Series lasers ensure unmatched stability and accuracy, empowering researchers and engineers to push the boundaries of what’s possible. The lasers are specifically suited for quantum technology research applications such as atom trapping, semiconductor inspection and laser pumping.
Ultralow-noise operation The Ampheia Series lasers are particularly suitable for quantum technology research applications. (Courtesy: HÜBNER Photonics)
In addition to the Ampheia Series, the new Cobolt Qu-T Series of single frequency, tunable lasers addresses atom cooling. With wavelengths of 707, 780 and 813 nm, course tunability of greater than 4 nm, narrow mode-hop free tuning of below 5 GHz, linewidth of below 50 kHz and powers of 500 mW, the Cobolt Qu-T Series is perfect for atom cooling of rubidium, strontium and other atoms used in quantum applications.
For the Raman spectroscopy market, HÜBNER Photonics announces the new Cobolt Disco single-frequency laser with available power of up to 500 mW at 785 nm, in a perfect TEM00 beam. This new wavelength is an extension of the Cobolt 05-01 Series platform, which with excellent wavelength stability, a linewidth of less than 100 kHz and spectral purity better than 70 dB, provides the performance needed for high-resolution, ultralow-frequency Raman spectroscopy measurements.
For life science applications, a number of new wavelengths and higher power levels are available, including 553 nm with 100 mW and 594 nm with 150 mW. These new wavelengths and power levels are available on the Cobolt 06-01 Series of modulated lasers, which offer versatile and advanced modulation performance with perfect linear optical response, true OFF states and stable illumination from the first pulse – for any duty cycles and power levels across all wavelengths.
The company’s unique multi-line laser, Cobolt Skyra, is now available with laser lines covering the full green–orange spectral range, including 594 nm, with up to 100 mW per line. This makes this multi-line laser highly attractive as a compact and convenient illumination source in most bioimaging applications, and now also specifically suitable for excitation of AF594, mCherry, mKate2 and other red fluorescent proteins.
In addition, with the Cobolt Kizomba laser, the company is introducing a new UV wavelength that specifically addresses the flow cytometry market. The Cobolt Kizomba laser offers 349 nm output at 50 mW with the renowned performance and reliability of the Cobolt 05-01 Series lasers.
Visit HÜBNER Photonics at the APS Global Summit, at booth #359.
Quantum technologies are flourishing the world over, with advances across the board researching practical applications such as quantum computing, communication, cryptography and sensors. Indeed, the quantum industry is booming – an estimated $42bn was invested in the sector in 2023, and this amount is projected to rise to $106bn by 2040.
With academia, industry and government all looking for professionals to join the future quantum workforce, it’s crucial to have people with the right skills, and from all educational levels. With this in mind, efforts are being made across the US to focus on quantum education and training, with educators working to introduce quantum concepts from the elementary-school level, all the way to tailored programmes at PhD and postgraduate level that meet the needs of potential employers in the area. Efforts are being made to ensure that graduates and early-career physicists are aware of the many roles available in the quantum sphere.
“There are a lot of layers to what has to be done in quantum education,” says Emily Edwards, an electrical and computer engineer at Duke University and co-leader of the National Q-12 Education Partnership. “I like to think of quantum education along different dimensions. One way is to think about what most learners may need in terms of foundational public literacy or student literacy in the space. Towards the top, we have people who are very specialized. Essentially, we have to think about many different learners at different stages – they might need specific tools or might need different barriers removed for them. And so different parts of the economy – from government to industry to academia and professional institutions – will play a role in how to address the needs of a certain group.”
Engaging young minds
To ensure that the US remains a key global player in quantum information science and technology (QIST), the National Q-12 Education Partnership – launched by the White House Office of Science and Technology Policy and the National Science Foundation (NSF) – is focused on ways to engage young minds in quantum, building the necessary tools and strategies to help improve early (K-12) education and outreach.
To achieve this, Q-12 is looking at outreach and education in middle and high school by introducing QIST concepts and providing access to learning materials and to inspire the next generation of quantum leaders. Over the next decade, Q-12 also aims to provide quantum-related curricula – developed by professionals in the field – beyond university labs and classrooms, to community colleges and online courses.
Edwards explains that while Q-12 mainly focuses on the K-12 level, there is also an overlap with early undergraduate, two-year colleges– meaning that there is a wide range of requirements, issues and unique challenges to contend with. Such a big space also means that different companies and institutions have varying levels of funding and interests in quantum education research and development.
“Academic organizations, for example, tend to work on educational research or to provide professional development, especially because it’s nascent,” says Edwards. “There is a lot of the activity in the academic space, within professional societies. We also work with a number of private companies, some of which are developing curricula, or providing free access to different tools and simulations for learning experiences.”
The role of the APS
The American Physical Society (APS) is strongly involved in quantum education – by making sure that teachers have access to tools and resources for quantum education as well as connecting quantum professionals with K-12 classrooms to discuss careers in quantum. “The APS has been really active in engaging with teachers and connecting them with the vast network of APS members, stakeholders and professionals, to talk about careers,” says Edwards. APS and Q-12 have a number of initiatives – such as Quantum To-Go and QuanTime – that help connect quantum professionals with classrooms and provide teachers with ready-to-use quantum activities.
Role model The Quantum To-Go programme matches scientists, engineers and professionals in quantum information science andt technology with classrooms across the US to inspire students to enter the quantum workforce. (Courtesy: APS)
Claudia Fracchiolla, who is the APS’s head of public engagement, points out that while there is growing interest in quantum education, there is a lack of explicit support for high-school teachers who need to be having conversations about a possible career in quantum with students that will soon be choosing a major.
“We know from our research that while teachers might want to engage in this professional development, they don’t always have the necessary support from their institution and it is not regulated,” explains Fracchiolla. She adds that while there are a “few stellar people in the field who are creating materials for teachers”, there is not a clear standard on how they can be used, or what can be taught at a school level.
Quantum To-Go
To help tackle these issues, the APS and Q-12 launched the Quantum To-Go programme, which pairs educators with quantum-science professionals, who speak to students about quantum concepts and careers. The programme covers students from the first year of school through to undergraduate level, with scientists visiting in person or virtually.
It’s a really great way for quantum professionals in different sectors to visit classrooms and talk about their experiences
Emily Edwards
“I think it’s a really great way for quantum professionals in different sectors to visit classrooms and talk about their experiences,” says Edwards. She adds that this kind of collaboration can be especially useful “because we know that students– particularly young women, or students of colour or those from any marginalized background – self-select out of these areas while they’re still in the K-12 environment.”
Edwards puts this down to a lack of role models in the workplace. “Not only do they not hear about quantum in the classroom or in their curriculum, but they also can’t see themselves working in the field,” she says. “So there’s no hope of achieving a diverse workforce if you don’t connect a diverse set of professionals with the classroom. So we are really proud to be a part of Quantum To-Go.”
Quantum resources
With 2025 being celebrated as the International Year of Quantum Science and Technology (IYQ), both Q-12 and the APS hope to see and host many community-driven activities and events focused on young learners and their families. An example of this is Q-12’s QuanTime initiative, which seeks to help teachers curate informal quantum activities across the US all year round. “Education is local in the US, and so it’s most successful if we can work with locals to help develop their own community resources,” explains Edwards.
A key event in the APS’s annual calendar of activities celebrating IYQ is the Quantum Education and Policy Summit, held in partnership with the Q-SEnSE institute. It aims to bring together key experts in physics education, policymakers and quantum industry leaders, to develop quantum educational resources and policies.
Quantum influencers Testifying before the US House Science Committee on 7 June 2023 were (from left to right) National Quantum Coordination Office director Charles Tahan, former Department of Education under secretary for science Paul Dabbar, NASA quantum scientist Eleanor Rieffel, Quantum Economic Development Consortium executive director Celia Merzbacher, and University of Illinois quantum scientist Emily Edwards (now at Duke University). (Courtesy: House Science Committee)
Another popular resource produced by the APS is its PhysicsQuest kits, which are aimed at middle-school students to help them explore specific physics topics. “We engaged with different APS members who work in quantum to design activities for middle-school students,”says Fracchiolla. “We then worked with some teachers to pilot and test those activities, before finalizing our kits, which are freely available to teachers. Normally, each year we do four activities, but thanks to IYQ, we decided to double that to eight activities that are all related to topics in quantum science and technology.”
To help distribute these kits to teachers, as well as provide them with guidance on how to use all the included materials, the APS is hosting workshops for teachers during the Teachers’ Days at the APS Global Physics Summit in March 2025. Workshops will also be held at the APS Division of Atomic, Molecular and Optical Physics (DAMOP) annual meeting in June.
“A key part of IYQ is creating an awareness of what quantum science and technology entails, because it is also about the people that work in the field,” says Fracchiolla. “Something that was really important when we were writing the proposal to send to the UN for the IYQ was to demonstrate how quantum technologies will supports the UN’s sustainable development goals. I hope this also inspires students to pursue careers in quantum, as they realize that it goes beyond quantum computing.”
If we are focusing on quantum technologies to address sustainable development goals, we need to make sure that they are accessible to everyone
Claudia Fracchiolla
Fracchiolla also underlines that having a diverse range of people in the quantum workforce will ensure that these technologies will help to tackle societal and environmental issues, and vice versa. “If we are focusing on quantum technologies to address sustainable development goals, we need to make sure that they are accessible to everyone. And that’s not going to happen if diverse minds are not involved in the process of developing these technologies,” she says, while acknowledging that this is currently not the case.
It is Fracchiolla’s ultimate hope that the IYQ and the APS’s activities taken together will help all students feel empowered that there is a place for them in the field. “Quantum is still a nascent field and we have the opportunity to not repeat the errors of the past, that have made many areas of science exclusive. We need to make the field diverse from the get go.”
In this episode of the Physics World Weekly podcast, we explore how computational physics is being used to develop new quantum materials; and we look at how ultrasound can help detect breast cancer.
Our first guest is Bhaskaran Muralidharan, who leads the Computational Nanoelectronics & Quantum Transport Group at the Indian Institute of Technology Bombay. In a conversation with Physics World’s Hamish Johnston, he explains how computational physics is being used to develop new materials and devices for quantum science and technology. He also shares his personal perspective on quantum physics in this International Year of Quantum Science and Technology.
Our second guest is Daniel Sarno of the UK’s National Physical Laboratory, who is an expert in the medical uses of ultrasound. In a conversation with Physics World’s Tami Freeman, Sarno explains why conventional mammography can struggle to detect cancer in patients with higher density breast tissue. This is a particular problem because women with such tissue are at higher risk of developing the disease. To address this problem, Sarno and colleagues have developed a ultrasound technique for measuring tissue density and are commercializing it via a company called sona.
Bhaskaran Muralidharan is an editorial board member on Materials for Quantum Technology. The journal is produced by IOP Publishing, which also brings you Physics World
The Superconducting Quantum Materials and Systems (SQMS) Center, led by Fermi National Accelerator Laboratory (Chicago, Illinois), is on a mission “to develop beyond-the-state-of-the-art quantum computers and sensors applying technologies developed for the world’s most advanced particle accelerators”. SQMS director Anna Grassellino talks to Physics World about the evolution of a unique multidisciplinary research hub for quantum science, technology and applications.
What’s the headline take on SQMS?
Established as part of the US National Quantum Initiative (NQI) Act of 2018, SQMS is one of the five National Quantum Information Science Research Centers run by the US Department of Energy (DOE). With funding of $115m through its initial five-year funding cycle (2020-25), SQMS represents a coordinated, at-scale effort – comprising 35 partner institutions – to address pressing scientific and technological challenges for the realization of practical quantum computers and sensors, as well as exploring how novel quantum tools can advance fundamental physics.
Our mission is to tackle one of the biggest cross-cutting challenges in quantum information science: the lifetime of superconducting quantum states – also known as the coherence time (the length of time that a qubit can effectively store and process information). Understanding and mitigating the physical processes that cause decoherence – and, by extension, limit the performance of superconducting qubits – is critical to the realization of practical and useful quantum computers and quantum sensors.
How is the centre delivering versus the vision laid out in the NQI?
SQMS has brought together an outstanding group of researchers who, collectively, have utilized a suite of enabling technologies from Fermilab’s accelerator science programme – and from our network of partners – to realize breakthroughs in qubit chip materials and fabrication processes; design and development of novel quantum devices and architectures; as well as the scale-up of complex quantum systems. Central to this endeavour are superconducting materials, superconducting radiofrequency (SRF) cavities and cryogenic systems – all workhorse technologies for particle accelerators employed in high-energy physics, nuclear physics and materials science.
Collective endeavour At the core of SQMS success are top-level scientists and engineers leading the centre’s cutting-edge quantum research programmes. From left to right: Alexander Romanenko, Silvia Zorzetti, Tanay Roy, Yao Lu, Anna Grassellino, Akshay Murthy, Roni Harnik, Hank Lamm, Bianca Giaccone, Mustafa Bal, Sam Posen. (Courtesy: Hannah Brumbaugh/Fermilab)
Take our research on decoherence channels in quantum devices. SQMS has made significant progress in the fundamental science and mitigation of losses in the oxides, interfaces, substrates and metals that underpin high-coherence qubits and quantum processors. These advances – the result of wide-ranging experimental and theoretical investigations by SQMS materials scientists and engineers – led, for example, to the demonstration of transmon qubits (a type of charge qubit exhibiting reduced sensitivity to noise) with systematic improvements in coherence, record-breaking lifetimes of over a millisecond, and reductions in performance variation.
How are you building on these breakthroughs?
First of all, we have worked on technology transfer. By developing novel chip fabrication processes together with quantum computing companies, we have contributed to our industry partners’ results of up to 2.5x improvement in error performance in their superconducting chip-based quantum processors.
We have combined these qubit advances with Fermilab’s ultrahigh-coherence 3D SRF cavities: advancing our efforts to build a cavity-based quantum processor and, in turn, demonstrating the longest-lived superconducting multimode quantum processor unit ever built (coherence times in excess of 20 ms). These systems open the path to a more powerful qudit-based quantum computing approach. (A qudit is a multilevel quantum unit that can be more than two states.) What’s more, SQMS has already put these novel systems to use as quantum sensors within Fermilab’s particle physics programme – probing for the existence of dark-matter candidates, for example, as well as enabling precision measurements and fundamental tests of quantum mechanics.
Elsewhere, we have been pushing early-stage societal impacts of quantum technologies and applications – including the use of quantum computing methods to enhance data analysis in magnetic resonance imaging (MRI). Here, SQMS scientists are working alongside clinical experts at New York University Langone Health to apply quantum techniques to quantitative MRI, an emerging diagnostic modality that could one day provide doctors with a powerful tool for evaluating tissue damage and disease.
What technologies pursued by SQMS will be critical to the scale-up of quantum systems?
There are several important examples, but I will highlight two of specific note. For starters, there’s our R&D effort to efficiently scale millikelvin-regime cryogenic systems. SQMS teams are currently developing technologies for larger and higher-cooling-power dilution refrigerators. We have designed and prototyped novel systems allowing over 20x higher cooling power, a necessary step to enable the scale-up to thousands of superconducting qubits per dilution refrigerator.
Materials insights The SQMS collaboration is studying the origins of decoherence in state-of-the-art qubits (above) using a raft of advanced materials characterization techniques – among them time-of-flight secondary-ion mass spectrometry, cryo electron microscopy and scanning probe microscopy. With a parallel effort in materials modelling, the centre is building a hierarchy of loss mechanisms that is informing how to fabricate the next generation of high-coherence qubits and quantum processors. (Courtesy: Dan Svoboda/Fermilab)
Also, we are working to optimize microwave interconnects with very low energy loss, taking advantage of SQMS expertise in low-loss superconducting resonators and materials in the quantum regime. (Quantum interconnects are critical components for linking devices together to enable scaling to large quantum processors and systems.)
How important are partnerships to the SQMS mission?
Partnerships are foundational to the success of SQMS. The DOE National Quantum Information Science Research Centers were conceived and built as mini-Manhattan projects, bringing together the power of multidisciplinary and multi-institutional groups of experts. SQMS is a leading example of building bridges across the “quantum ecosystem” – with other national and federal laboratories, with academia and industry, and across agency and international boundaries.
In this way, we have scaled up unique capabilities – multidisciplinary know-how, infrastructure and a network of R&D collaborations – to tackle the decoherence challenge and to harvest the power of quantum technologies. A case study in this regard is Ames National Laboratory, a specialist DOE centre for materials science and engineering on the campus of Iowa State University.
Ames is a key player in a coalition of materials science experts – coordinated by SQMS – seeking to unlock fundamental insights about qubit decoherence at the nanoscale. Through Ames, SQMS and its partners get access to powerful analytical tools – modalities like terahertz spectroscopy and cryo transmission electron microscopy – that aren’t routinely found in academia or industry.
What are the drivers for your engagement with the quantum technology industry?
The SQMS strategy for industry engagement is clear: to work hand-in-hand to solve technological challenges utilizing complementary facilities and expertise; to abate critical performance barriers; and to bring bidirectional value. I believe that even large companies do not have the ability to achieve practical quantum computing systems working exclusively on their own. The challenges at hand are vast and often require R&D partnerships among experts across diverse and highly specialized disciplines.
I also believe that DOE National Laboratories – given their depth of expertise and ability to build large-scale and complex scientific instruments – are, and will continue to be, key players in the development and deployment of the first useful and practical quantum computers. This means not only as end-users, but as technology developers. Our vision at SQMS is to lay the foundations of how we are going to build these extraordinary machines in partnership with industry. It’s about learning to work together and leveraging our mutual strengths.
How do Rigetti and IBM, for example, benefit from their engagement with SQMS?
The partnership with IBM, although more recent, is equally significant. Together with IBM researchers, we are interested in developing quantum interconnects – including the development of high-Q cables to make them less lossy – for the high-fidelity connection and scale-up of quantum processors into large and useful quantum computing systems.
At the same time, SQMS scientists are exploring simulations of problems in high-energy physics and condensed-matter physics using quantum computing cloud services from Rigetti and IBM.
Presumably, similar benefits accrue to suppliers of ancillary equipment to the SQMS quantum R&D programme?
Correct. We challenge our suppliers of advanced materials and fabrication equipment to go above and beyond, working closely with them on continuous improvement and new product innovation. In this way, for example, our suppliers of silicon and sapphire substrates and nanofabrication platforms – key technologies for advanced quantum circuits – benefit from SQMS materials characterization tools and fundamental physics insights that would simply not be available in isolation. These technologies are still at a stage where we need fundamental science to help define the ideal materials specifications and standards.
We are also working with companies developing quantum control boards and software, collaborating on custom solutions to unique hardware architectures such as the cavity-based qudit platforms in development at Fermilab.
How is your team building capacity to support quantum R&D and technology innovation?
We’ve pursued a twin-track approach to the scaling of SQMS infrastructure. On the one hand, we have augmented – very successfully – a network of pre-existing facilities at Fermilab and at SQMS partners, spanning accelerator technologies, materials science and cryogenic engineering. In aggregate, this covers hundreds of millions of dollars’ worth of infrastructure that we have re-employed or upgraded for studying quantum devices, including access to a host of leading-edge facilities via our R&D partners – for example, microkelvin-regime quantum platforms at Royal Holloway, University of London, and underground quantum testbeds at INFN’s Gran Sasso Laboratory.
Thinking big in quantum The SQMS Quantum Garage (above) houses a suite of R&D testbeds to support granular studies of superconducting qubits, quantum processors, high-coherence quantum sensors and quantum interconnects. (Courtesy: Ryan Postel/Fermilab)
In parallel, we have invested in new and dedicated infrastructure to accelerate our quantum R&D programme. The Quantum Garage here at Fermilab is the centrepiece of this effort: a 560 square-metre laboratory with a fleet of six additional dilution refrigerators for cryogenic cooling of SQMS experiments as well as test, measurement and characterization of superconducting qubits, quantum processors, high-coherence quantum sensors and quantum interconnects.
What is the vision for the future of SQMS?
SQMS is putting together an exciting proposal in response to a DOE call for the next five years of research. Our efforts on coherence will remain paramount. We have come a long way, but the field still needs to make substantial advances in terms of noise reduction of superconducting quantum devices. There’s great momentum and we will continue to build on the discoveries made so far.
We have also demonstrated significant progress regarding our 3D SRF cavity-based quantum computing platform. So much so that we now have a clear vision of how to implement a mid-scale prototype quantum computer with over 50 qudits in the coming years. To get us there, we will be laying out an exciting SQMS quantum computing roadmap by the end of 2025.
It’s equally imperative to address the scalability of quantum systems. Together with industry, we will work to demonstrate practical and economically feasible approaches to be able to scale up to large quantum computing data centres with millions of qubits.
Finally, SQMS scientists will work on exploring early-stage applications of quantum computers, sensors and networks. Technology will drive the science, science will push the technology – a continuous virtuous cycle that I’m certain will lead to plenty more ground-breaking discoveries.
How SQMS is bridging the quantum skills gap
Education, education, education SQMS hosted the inaugural US Quantum Information Science (USQIS) School in summer 2023. Held annually, the USQIS is organized in conjunction with other DOE National Laboratories, academia and industry. (Courtesy: Dan Svoboda/Fermilab)
As with its efforts in infrastructure and capacity-building, SQMS is addressing quantum workforce development on multiple fronts.
Across the centre, Grassellino and her management team have recruited upwards of 150 technical staff and early-career researchers over the past five years to accelerate the SQMS R&D effort. “These ‘boots on the ground’ are a mix of PhD students, postdoctoral researchers plus senior research and engineering managers,” she explains.
Another significant initiative was launched in summer 2023, when SQMS hosted nearly 150 delegates at Fermilab for the inaugural US Quantum Information Science (USQIS) School – now an annual event organized in conjunction with other National Laboratories, academia and industry. The long-term goal is to develop the next generation of quantum scientists, engineers and technicians by sharing SQMS know-how and experimental skills in a systematic way.
“The prioritization of quantum education and training is key to sustainable workforce development,” notes Grassellino. With this in mind, she is currently in talks with academic and industry partners about an SQMS-developed master’s degree in quantum engineering. Such a programme would reinforce the centre’s already diverse internship initiatives, with graduate students benefiting from dedicated placements at SQMS and its network partners.
“Wherever possible, we aim to assign our interns with co-supervisors – one from a National Laboratory, say, another from industry,” adds Grassellino. “This ensures the learning experience shapes informed decision-making about future career pathways in quantum science and technology.”
Researchers at Microsoft in the US claim to have made the first topological quantum bit (qubit) – a potentially transformative device that could make quantum computing robust against the errors that currently restrict what it can achieve. “If the claim stands, it would be a scientific milestone for the field of topological quantum computing and physics beyond,” says Scott Aaronson, a computer scientist at the University of Texas at Austin.
However, the claim is controversial because the evidence supporting it has not yet been presented in a peer-reviewed paper. It is made in a press release from Microsoft accompanying a paper in Nature (638 651) that has been written by more than 160 researchers from the company’s Azure Quantum team. The paper stops short of claiming a topological qubit but instead reports some of the key device characterization underpinning it.
Writing in a peer-review file accompanying the paper, the Nature editorial team says that it sought additional input from two of the article’s reviewers to “establish its technical correctness”, concluding that “the results in this manuscript do not represent evidence for the presence of Majorana zero modes [MZMs] in the reported devices”. An MZM is a quasiparticle (a particle-like collective electronic state) that can act as a topological qubit.
“That’s a big no-no”
“The peer-reviewed publication is quite clear [that it contains] no proof for topological qubits,” says Winfried Hensinger, a physicist at the University of Sussex who works on quantum computing using trapped ions. “But the press release speaks differently. In academia that’s a big no-no: you shouldn’t make claims that are not supported by a peer-reviewed publication” – or that have at least been presented in a preprint.
Chetan Nayak, leader of Microsoft Azure Quantum, which is based in Redmond, Washington, says that the evidence for a topological qubit was obtained in the period between submission of the paper in March 2024 and its publication. He will present those results at a talk at the Global Physics Summit of the American Physical Society in Anaheim in March.
But Hensinger is concerned that “the press release doesn’t make it clear what the paper does and doesn’t contain”. He worries that some might conclude that the strong claim of having made a topological qubit is now supported by a paper in Nature. “We don’t need to make these claims – that is just unhealthy and will really hurt the field,” he says, because it could lead to unrealistic expectations about what quantum computers can do.
As with the qubits used in current quantum computers, such as superconducting components or trapped ions, MZMs would be able to encode superpositions of the two readout states (representing a 1 or 0). By quantum-entangling such qubits, information could be manipulated in ways not possible for classical computers, greatly speeding up certain kinds of computation. In MZMs the two states are distinguished by “parity”: whether the quasiparticles contain even or odd numbers of electrons.
Built-in error protection
As MZMs are “topological” states, their settings cannot easily be flipped by random fluctuations to introduce errors into the calculation. Rather, the states are like a twist in a buckled belt that cannot be smoothed out unless the buckle is undone. Topological qubits would therefore suffer far less from the errors that afflict current quantum computers, and which limit the scale of the computations they can support. Because quantum error correction is one of the most challenging issues for scaling up quantum computers, “we want some built-in level of error protection”, explains Nayak.
It has long been thought that MZMs might be produced at the ends of nanoscale wires made of a superconducting material. Indeed, Microsoft researchers have been trying for several years to fabricate such structures and look for the characteristic signature of MZMs at their tips. But it can be hard to distinguish this signature from those of other electronic states that can form in these structures.
In 2018 researchers at labs in the US and the Netherlands (including the Delft University of Technology and Microsoft), claimed to have evidence of an MZM in such devices. However, they then had to retract the work after others raised problems with the data. “That history is making some experts cautious about the new claim,” says Aaronson.
Now, though, it seems that Nayak and colleagues have cracked the technical challenges. In the Nature paper, they report measurements in a nanowire heterostructure made of superconducting aluminium and semiconducting indium arsenide that are consistent with, but not definitive proof of, MZMs forming at the two ends. The crucial advance is an ability to accurately measure the parity of the electronic states. “The paper shows that we can do these measurements fast and accurately,” says Nayak.
The device is a remarkable achievement from the materials science and fabrication standpoint
Ivar Martin, Argonne National Laboratory
“The device is a remarkable achievement from the materials science and fabrication standpoint,” says Ivar Martin, a materials scientist at Argonne National Laboratory in the US. “They have been working hard on these problems, and seems like they are nearing getting the complexities under control.” In the press release, the Microsoft team claims now to have put eight MZM topological qubits on a chip called Majorana 1, which is designed to house a million of them (see figure).
Even if the Microsoft claim stands up, a lot will still need to be done to get from a single MZM to a quantum computer, says Hensinger. Topological quantum computing is “probably 20–30 years behind the other platforms”, he says. Martin agrees. “Even if everything checks out and what they have realized are MZMs, cleaning them up to take full advantage of topological protection will still require significant effort,” he says.
Regardless of the debate about the results and how they have been announced, researchers are supportive of the efforts at Microsoft to produce a topological quantum computer. “As a scientist who likes to see things tried, I’m grateful that at least one player stuck with the topological approach even when it ended up being a long, painful slog,” says Aaronson.
“Most governments won’t fund such work, because it’s way too risky and expensive,” adds Hensinger. “So it’s very nice to see that Microsoft is stepping in there.”
The processor uses qubits that can be measured without error and are resistant to outside interference, which the company says marks a “transformative leap toward practical quantum computing.”
2 In quantum cryptography, who eavesdrops on Alice and Bob?
(Courtesy: Andy Roberts IBM Research/Science Photo Library)
3 Which artist made the Quantum Cloud sculpture in London?
4 IBM used which kind of atoms to create its Quantum Mirage image?
5 When Werner Heisenberg developed quantum mechanics on Helgoland in June 1925, he had travelled to the island to seek respite from what? A His allergies B His creditors C His funders D His lovers
6 According to the State of Quantum 2024 report, how many countries around the world had government initiatives in quantum technology at the time of writing? A 6 B 17 C 24 D 33
7 The E91 quantum cryptography protocol was invented in 1991. What does the E stand for? A Edison B Ehrenfest C Einstein D Ekert
8 British multinational consumer-goods firm Reckitt sells a “Quantum” version of which of its household products? A Air Wick freshener B Finish dishwasher tablets C Harpic toilet cleaner D Vanish stain remover
9 John Bell’s famous theorem of 1964 provides a mathematical framework for understanding what quantum paradox? A Einstein–Podolsky–Rosen B Quantum indefinite causal order C Schrödinger’s cat D Wigner’s friend
10 Which celebrated writer popularized the notion of Schrödinger’s cat in the mid-1970s? A Douglas Adams B Margaret Atwood C Arthur C Clarke D Ursula K le Guin
11 Which of these isn’t an interpretation of quantum mechanics? A Copenhagen B Einsteinian C Many worlds D Pilot wave
12 Which of these companies is not a real quantum company? A Qblox B Qruise C Qrypt D Qtips
13 Which celebrity was spotted in the audience at a meeting about quantum computers and music in London in December 2022? A Peter Andre B Peter Capaldi C Peter Gabriel D Peter Schmeichel
14 What of the following birds has not yet been chosen by IBM as the name for different versions of its quantum hardware? A Condor B Eagle C Flamingo D Peregrine
15 When quantum theorist Erwin Schrödinger fled Nazi-controlled Vienna in 1938, where did he hide his Nobel-prize medal? A In a filing cabinet B Under a pot plant C Behind a sofa D In a desk drawer
16 Which of the following versions of the quantum Hall effect has not been observed so far in the lab? A Fractional quantum Hall effect B Anomalous fractional quantum Hall effect C Anyonic fractional quantum Hall effect D Excitonic fractional quantum Hall effect
17 What did Quantum Coffee on Front Street West in Toronto call its recently launched pastry, which is a superposition of a croissant and muffin? A Croissin B Cruffin C Muffant D Muffcro
18 What destroyed the Helgoland guest house where Heisenberg stayed in 1925 while developing quantum mechanics? A A bomb B A gas leak C A rat infestation D A storm
This quiz is for fun and there are no prizes. Answers will be revealed on the Physics World website in April.
This article forms part of Physics World‘s contribution to the 2025 International Year of Quantum Science and Technology (IYQ), which aims to raise global awareness of quantum physics and its applications.
Stayed tuned to Physics World and our international partners throughout the next 12 months for more coverage of the IYQ.
The United Nations Educational, Scientific and Cultural Organization (UNESCO) has declared 2025 the International Year of Quantum Science and Technology – or IYQ.
UNESCO kicked-off IYQ on 4–5 February at a gala opening ceremony in Paris. Physics World’s Matin Durrani was there, and he shares his highlights from the event in this episode of the Physics World Weekly podcast.
No fewer than four physics Nobel laureates took part in the ceremony alongside representatives from governments and industry. While some speakers celebrated the current renaissance in quantum research and the burgeoning quantum-technology sector, others called on the international community to ensure that people in all nations benefit from a potential quantum revolution – not just people in wealthier countries. The dangers of promising too much from quantum computers and other technologies, was also discussed – as Durrani explains.
IBM is on a mission to transform quantum computers from applied research endeavour to mainstream commercial opportunity. It wants to go beyond initial demonstrations of “quantum utility”, where these devices outperform classical computers only in a few niche applications, and reach the new frontier of “quantum advantage”. That’ll be where quantum computers routinely deliver significant, practical benefits beyond approximate classical computing methods, calculating solutions that are cheaper, faster and more accurate.
Unlike classical computers, which rely on the binary bits that can be either 0 or 1, quantum computers exploit quantum binary bits (qubits), but as a superposition of 0 and 1 states. This superposition, coupled with quantum entanglement (a correlation of two qubits), enables quantum computers to perform some types of calculation significantly faster than classical machines, such as problems in quantum chemistry and molecular reaction kinetics.
In the vanguard of IBM’s quantum R&D effort is Sarah Sheldon, a principal research scientist and senior manager of quantum theory and capabilities at the IBM Thomas J Watson Research Center in Yorktown Heights, New York. After a double-major undergraduate degree in physics and nuclear science and engineering at Massachusetts Institute of Technology (MIT), Sheldon received her PhD from MIT in 2013 – though she did much of her graduate research in nuclear science and engineering as a visiting scholar at the Institute for Quantum Computing (IQC) at the University of Waterloo, Canada.
At IQC, Sheldon was part of a group studying quantum control techniques, manipulating the spin states of nuclei in nuclear-magnetic-resonance (NMR) experiments. “Although we were using different systems to today’s leading quantum platforms, we were applying a lot of the same kinds of control techniques now widely deployed across the quantum tech sector,” Sheldon explains.
“Upon completion of my PhD, I opted instinctively for a move into industry, seeking to apply all that learning in quantum physics into immediate and practical engineering contributions,” she says. “IBM, as one of only a few industry players back then with an experimental group in quantum computing, was the logical next step.”
Physics insights, engineering solutions
Sheldon currently heads a cross-disciplinary team of scientists and engineers developing techniques for handling noise and optimizing performance in novel experimental demonstrations of quantum computers. It’s ambitious work that ties together diverse lines of enquiry spanning everything from quantum theory and algorithm development to error mitigation, error correction and techniques for characterizing quantum devices.
We’re investigating how to extract the optimum performance from current machines online today as well as from future generations of quantum computers.
Sarah Sheldon, IBM
“From algorithms to applications,” says Sheldon, “we’re investigating what can we do with quantum computers: how to extract the optimum performance from current machines online today as well as from future generations of quantum computers – say, five or 10 years down the line.”
A core priority for Sheldon and colleagues is how to manage the environmental noise that plagues current quantum computing systems. Qubits are all too easily disturbed, for example, by their interactions with environmental fluctuations in temperature, electric and magnetic fields, vibrations, stray radiation and even interference between neighbouring qubits.
The ideal solution – a strategy called error correction – involves storing the same information across multiple qubits, such that errors are detected and corrected when one or more of the qubits are impacted by noise. But the problem with these so-called “fault-tolerant” quantum computers is they need millions of qubits, which is impossible to implement in today’s small-scale quantum architectures. (For context, IBM’s latest Quantum Development Roadmap outlines a practical path to error-corrected quantum computers by 2029.)
“Ultimately,” Sheldon notes, “we’re working towards large-scale error-corrected systems, though for now we’re exploiting near-term techniques like error mitigation and other ways of managing noise in these systems.” In practical terms, this means implementing quantum architectures without increasing the number of qubits – essentially, integrating them with classical computers to reduce noise through increasing samples on the quantum computer combined with classical processing.
Strength in diversity
For Sheldon, one big selling point of the quantum tech industry is the opportunity to collaborate with people from a wide range of disciplines. “My team covers a broad-scope R&D canvas,” she says. There are mathematicians and computer scientists, for example, working on complexity theory and novel algorithm development; physicists specializing in quantum simulation and incorporating error suppression techniques; as well as quantum chemists working on simulations of molecular systems.
“Quantum is so interdisciplinary – you are constantly learning something new from your co-workers,” she adds. “I started out specializing in quantum control techniques, before moving onto experimental demonstrations of larger multiqubit systems while working ever more closely with theorists.”
Computing reimagined Quantum scientists and engineers at the IBM Thomas J Watson Research Center are working to deliver IBM’s Quantum Development Roadmap and a practical path to error-corrected quantum computers by 2029. (Courtesy: Connie Zhou for IBM)
External research collaborations are also mandatory for Sheldon and her colleagues. Front-and-centre is the IBM Quantum Network, which provides engagement opportunities with more than 250 organizations across the “quantum ecosystem”. These range from top-tier labs – such as CERN, the University of Tokyo and the UK’s National Quantum Computing Centre – to quantum technology start-ups like Q-CTRL and Algorithmiq. It also encompasses established industry players aiming to be early-adopting end-users of quantum technologies (among them Bosch, Boeing and HSBC).
“There’s a lot of innovation happening across the quantum community,” says Sheldon, “so external partnerships are incredibly important for IBM’s quantum R&D programme. While we have a deep and diverse skill set in-house, we can’t be the domain experts across every potential use-case for quantum computing.”
Opportunity knocks
Notwithstanding the pace of innovation, there are troubling clouds on the horizon. In particular, there is a shortage of skilled workers in the quantum workforce, with established technology companies and start-ups alike desperate to attract more physical scientists and engineers. The task is to fill not only specialist roles – be it error-correction scientists or quantum-algorithm developers – but more general positions such as test and measurement engineers, data scientists, cryogenic technicians and circuit designers.
Yet Sheldon remains upbeat about addressing the skills gap. “There are just so many opportunities in the quantum sector,” she notes. “The field has changed beyond all recognition since I finished my PhD.” Perhaps the biggest shift has been the dramatic growth of industry engagement and, with it, all sorts of attractive career pathways for graduate scientists and engineers. Those range from firms developing quantum software or hardware to the end-users of quantum technologies in sectors such as pharmaceuticals, finance or healthcare.
“As for the scientific community,” argues Sheldon, “we’re also seeing the outline take shape for a new class of quantum computational scientist. Make no mistake, students able to integrate quantum computing capabilities into their research projects will be at the leading edge of their fields in the coming decades.”
Ultimately, Sheldon concludes, early-career scientists shouldn’t necessarily over-think things regarding that near-term professional pathway. “Keep it simple and work with people you like on projects that are going to interest you – whether quantum or otherwise.”
A new type of quantum bit (qubit) that stores information in a quantum dot with the help of an ensemble of nuclear spin states has been unveiled by physicists in the UK and Austria. Led by Dorian Gangloff and Mete Atatüre at the University of Cambridge, the team created a collective quantum state that could be used as a quantum register to store and relay information in a quantum communication network of the future.
Quantum communication networks are used to exchange and distribute quantum information between remotely-located quantum computers and other devices. As well as enabling distributed quantum computing, quantum networks can also support secure quantum cryptography. Today, these networks are in the very early stages of development and use the entangled quantum states of photons to transmit information. Network performance is severely limited by decoherence, whereby the quantum information held by photons is degraded as they travel long distances. As a result, effective networks need repeater nodes that receive and then amplify weakened quantum signals.
“To address these limitations, researchers have focused on developing quantum memories capable of reliably storing entangled states to enable quantum repeater operations over extended distances,” Gangloff explains. “Various quantum systems are being explored, with semiconductor quantum dots being the best single-photon generators delivering both photon coherence and brightness.”
Single-photon emission
Quantum dots are widely used for their ability to emit single photons at specific wavelengths. These photons are created by electronic transitions in quantum dots and are ideal for encoding and transmitting quantum information.
However, the electronic spin states of quantum dots are not particularly good at storing quantum information for long enough to be useful as stationary qubits (or nodes) in a quantum network. This is because they contain hundreds or thousands of nuclei with spins that fluctuate. The noise generated by these fluctuations causes the decoherence of qubits based on electronic spin states.
In their previous research, Gangloff and Atatüre’s team showed how this noise could be controlled by sensing how it interacts with the electronic spin states.
Atatüre says, “Building on our previous achievements, we suppressed random fluctuations in the nuclear ensemble using a quantum feedback algorithm. This is already very useful as it dramatically improves the electron spin qubit performance.”
Magnon excitation
Now, using a gallium arsenide quantum dot, the team has used the feedback algorithm to stabilize 13,000 nuclear spin states in a collective, entangled “dark state”. This is a stable quantum state that cannot absorb or emit photons. By introducing just a single nuclear magnon (spin flip) excitation, shared across all 13,000 nuclei, they could then flip the entire ensemble between two different collective quantum states.
Each of these collective states could respectively be defined as a 0 and a 1 in a binary quantum logic system. The team then showed how quantum information could be exchanged between the nuclear system and the quantum dot’s electronic qubit with a fidelity of about 70%.
“The quantum memory maintained the stored state for approximately 130 µs, validating the effectiveness of our protocol,” Gangloff explains. “We also identified unambiguously the factors limiting the current fidelity and storage time, including crosstalk between nuclear modes and optically induced spin relaxation.”
The researchers are hopeful that their approach could transform one of the biggest limitations to quantum dot-based communication networks into a significant advantage.
“By integrating a multi-qubit register with quantum dots – the brightest and already commercially available single-photon sources – we elevate these devices to a much higher technology readiness level,” Atatüre explains.
With some further improvements to their system’s fidelity, the researchers are now confident that it could be used to strengthen interactions between quantum dot qubits and the photonic states they produce, ultimately leading to longer coherence times in quantum communication networks. Elsewhere, it could even be used to explore new quantum phenomena, and gather new insights into the intricate dynamics of quantum many-body systems.
Whether it’s the Olympics or the FIFA World Cup, all big global events need a cheeky, fun mascot. So welcome to Quinnie – the official mascot for the International Year of Quantum Science and Technology (IYQ) 2025.
Unveiled at the launch of the IYQ at the headquarters of UNESCO in Paris on 4 February, Quinnie has been drawn by Jorge Cham, the creator of the long-running cartoon strip PHD Comics.
Quinnie was developed for UNESCO in a collaboration between Cham and PhysicsMagazine, which is published by the American Physical Society (APS) – one of the founding partners of IYQ.
Riding high Quinnie surfing on a quantum wave function. (Courtesy: Jorge Cham)
“Quinnie represents a young generation approaching quantum science with passion, ingenuity, and energy,” says Physics editor Matteo Rini. “We imagine her effortlessly surfing on quantum-mechanical wave functions and playfully engaging with the knottiest quantum ideas, from entanglement to duality.”
Quinnie is set to appear in a series of animated cartoons that the APS will release throughout the year.
This article forms part of Physics World‘s contribution to the 2025 International Year of Quantum Science and Technology (IYQ), which aims to raise global awareness of quantum physics and its applications.
Stayed tuned to Physics World and our international partners throughout the next 12 months for more coverage of the IYQ.
More than 800 researchers, policy makers and government officials from around the world gathered in Paris this week to attend the official launch of the International Year of Quantum Science and Technology (IYQ). Held at the headquarters of the United Nations Educational, Scientific and Cultural Organisation (UNESCO), the two-day event included contributions from four Nobel prize-winning physicists – Alain Aspect, Serge Haroche, Anne l’Huillier and William Phillips.
Opening remarks came from Cephas Adjej Mensah, a research director in the Ghanaian government, which last year submitted the draft resolution to the United Nations for 2025 to be proclaimed as the IYQ. “Let us commit to making quantum science accessible to all,” Mensah declared, reminding delegates that the IYQ is intended to be a global initiative, spreading the benefits of quantum equitably around the world. “We can unleash the power of quantum science and technology to make an equitable and prosperous future for all.”
The keynote address was given by l’Huillier, a quantum physicist at Lund University in Sweden, who shared the 2023 Nobel Prize for Physics with Pierre Agostini and Ferenc Krausz for their work on attosecond pulses. “Quantum mechanics has been extremely successful,” she said, explaining how it was invented 100 years ago by Werner Heisenberg on the island of Helgoland. “It has led to new science and new technology – and it’s just the beginning.”
Let’s go Stephanie Simmons, chief quantum officer at Photonic and co-chair of Canada’s National Quantum Strategy advisory council, speaking at the IYQ launch in Paris. (Courtesy: Matin Durrani)
Some of that promise was outlined by Phillips in his plenary lecture. The first quantum revolution led to lasers, semiconductors and transistors, he reminded participants, but said that the second quantum revolution promises more by exploiting effects such as quantum entanglement and superposition – even if its potential can be hard to grasp. “It’s not that there’s something deeply wrong with quantum mechanics – it’s that there’s something deeply wrong with our ability to understand it,” Phillips explained.
The benefits of quantum technology to society were echoed by leading Chinese quantum physicist Jian-Wei Pan of the University of Science and Technology of China in Hefei. “The second quantum revolution will likely provide another human leap in human civilization,” said Pan, who was not at the meeting, in a pre-recorded video statement. “Sustainable funding from government and private sector is essential. Intensive and proactive international co-operation and exchange will undoubtedly accelerate the benefit of quantum information to all of humanity.”
Leaders of the burgeoning quantum tech sector were in Paris too. Addressing the challenges and opportunities of scaling quantum technologies to practical use was a panel made up of Quantinuum chief executive Rajeeb Hazra, QuEra president Takuya Kitawawa, IBM’s quantum-algorithms vice president Katie Pizzoalato, ID Quantique boss Grégoire Ribordy and Microsoft technical fellow Krysta Svore. Also present was Alexander Ling from the National University of Singapore, co-founder of two hi-tech start-ups.
“We cannot imagine what weird and wonderful things quantum mechanics will lead to but you can sure it’ll be marvellous,” said Celia Merzbacher, executive director of the Quantum Economic Development Consortium (QED-C), who chaired the session. All panellists stressed the importance of having a supply of talented quantum scientists and engineers if the industry is to succeed. Hamza also underlined that new products based on “quantum 2.0” technology had to be developed with – and to serve the needs of – users if they are to turn a profit.
The ethical challenges of quantum advancements were also examined in a special panel, as was the need for responsible quantum innovation to avoid a “digital divide” where quantum technology benefits some parts of society but not others. “Quantum science should elevate human dignity and human potential,” said Diederick Croese, a lawyer and director of the Centre for Quantum and Society at Quantum Delta NL in the Netherlands.
Science in action German artist Robin Baumgarten explains the physics behind his Quantum Jungle art installation. (Courtesy: Matin Durrani)
The cultural impact of quantum science and technology was not forgotten in Paris either. Delegates flocked to an art installation created by Berlin-based artist and game developer Robin Baumgarten. Dubbed Quantum Jungle, it attempts to “visualize quantum physics in a playful yet scientifically accurate manner” by using an array of lights controlled by flickable, bendy metal door stops. Baumgarten claims it is a “mathematically accurate model of a quantum object”, with the brightness of each ring being proportional to the chance of an object being there.
This article forms part of Physics World‘s contribution to the 2025 International Year of Quantum Science and Technology (IYQ), which aims to raise global awareness of quantum physics and its applications.
Stayed tuned to Physics World and our international partners throughout the next 12 months for more coverage of the IYQ.
Watch this short video filmed at the APS March Meeting in 2024, where Mark Elo, chief marketing officer of Tabor Quantum Solutions, introduces the Echo-5Q, which he explains is an industry collaboration between FormFactor and Tabor Quantum Solutions, using the QuantWare quantum processing unit (QPU).
Elo points out that it is an out-of-the-box solution, allowing customers to order a full-stack system, including the software, refrigeration, control electronics and the actual QPU. With the Echo-5, it gets delivered and installed, so that the customer can start doing quantum measurements immediately. He explains that the Echo-5Q is designed at a price and feature point that increases the accessibility for on-site quantum computing.
Brandon Boiko, senior applications engineer with FormFactor, describes the how FormFactor developed the dilution refrigeration technology that the qubits get installed into. Boiko explains that the product has been designed to reduce the cost of entry into the quantum field – made accessible through FormFactor’s test-and- measurement programme, which allows people to bring their samples on site to take measurements.
Alessandro Bruno is founder and CEO of QuantWare, which provides the quantum processor for the Echo-5Q, the part that sits at the milli Kelvin stage of the dilution refrigerator, and that hosts five qubits. Bruno hopes that the Echo-5Q will democratize access to quantum devices – for education, academic research and start-ups.
I am one of two co-chairs, along with my colleague Hendrik Ohldag, of the Quantum Materials Research and Discovery Thrust Area at ALS. Among other things, our remit is to advise ALS management on long-term strategy regarding quantum science, We launch and manage beamline development projects to enhance the quantum research capability at ALS and, more broadly, establish collaborations with quantum scientists and engineers in academia and industry.
In terms of specifics, the thrust area addresses problems of condensed-matter physics related to spin and quantum properties – for example, in atomically engineered multilayers, 2D materials and topological insulators with unusual electronic structures. As a beamline scientist, active listening is the key to establishing productive research collaborations with our scientific end-users – helping them to figure out the core questions they’re seeking to answer and, by extension, the appropriate experimental techniques to generate the data they need.
The task, always, is to translate external users’ scientific goals into practical experiments that will run reliably on the ALS beamlines. High-level organizational skills, persistence and exhaustive preparation go a long way: it takes a lot of planning and dialogue to ensure scientific users get high-quality experimental results.
What do you like best and least about your job?
A core part of my remit is to foster the collective conversation between ALS staff scientists and the quantum community, demystifying synchrotron science and the capabilities of the ALS with prospective end-users. The outreach activity is exciting and challenging in equal measure – whether that’s initiating dialogue with quantum experts at scientific conferences or making first contact using Teams or Zoom.
Internally, we also track the latest advances in fundamental quantum science and applied R&D. In-house colloquia are mandatory, with guest speakers from the quantum community engaging directly with ALS staff teams to figure out how our portfolio of synchrotron-based techniques – whether spectroscopy, scattering or imaging – can be put to work by users from research or industry. This learning and development programme, in turn, underpins continuous improvement of the beamline support services we offer to all our quantum end-users.
As for downsides: it’s never ideal when a piece of instrumentation suddenly “breaks” on a Friday afternoon. This sort of troubleshooting is probably the part of the job I like least, though it doesn’t happen often and, in any case, is a hit I’m happy to take given the flexibility inherent to my role.
What do you know today that you wish you knew when you were starting out in your career?
It’s still early days, but I guess the biggest lesson so far is to trust in my own specialist domain knowledge and expertise when it comes to engaging with the diverse research community working on quantum materials. My know-how in photon science – from coherent X-ray scattering and X-ray detector technology to in situ magnetic- and electric-field studies and automated measurement protocols – enables visiting researchers to get the most out of their beamtime at ALS.
This video has no voice over. (Video courtesy: Space Production)
The aim of the International Year of Quantum Science & Technology (IYQ) in 2025 to help raise the public’s awareness of the importance and impact of quantum science and applications on all aspects of life.
Ukraine-born artist Oksana Kondratyeva has certainly taken that message to heart. A London-based designer and producer of architectural glass art, she has recently created an intriguing piece of stained glass inspired by the casing for a quantum computer.
In this video specially made by Kondratyeva for Physics World, you can see her artwork, which was displayed at the 2024 British Glass Biennale, and glimpse the artist in the protective gear she wears while working with the chemicals to make her piece.
In the feature, Kondratyeva describes how her work fuses science and art – and reveals how the collaboration with Rigetti came about. As it happens, it was an article in Physics World during another international year – devoted to glass – that inspired the project.
Brilliant mind Illustration of the Danish physicist and Nobel laureate Niels Bohr (1885-1962). Bohr made numerous contributions to physics during his career, but it was his work on atomic structure and quantum theory that won him the 1922 Nobel Prize for Physics. (Courtesy: Sam Falconer, Debut Art/Science Photo Library)
One hundred and one years ago, Danish physicist Niels Bohr proposed a radical theory together with two young colleagues – Hendrik Kramers and John Slater – in an attempt to resolve some of the most perplexing issues in fundamental physics at the time. Entitled “The Quantum Theory of Radiation”, and published in the Philosophical Magazine, their hypothesis was quickly proved wrong, and has since become a mere footnote in the history of quantum mechanics.
Despite its swift demise, their theory perfectly illustrates the sense of crisis felt by physicists at that moment, and the radical ideas they were prepared to contemplate to resolve it. For in their 1924 paper Bohr and his colleagues argued that the discovery of the “quantum of action” might require the abandonment of nothing less than the first law of thermodynamics: the conservation of energy.
As we celebrate the centenary of Werner Heisenberg’s 1925 quantum breakthrough with the International Year of Quantum Science and Technology (IYQ) 2025, Bohr’s 1924 paper offers a lens through which to look at how the quantum revolution unfolded. Most physicists at that time felt that if anyone was going to rescue the field from the crisis, it would be Bohr. Indeed, this attempt clearly shows signs of the early rift between Bohr and Albert Einstein about the quantum realm, that would turn into a lifelong argument. Remarkably, the paper also drew on an idea that later featured in one of today’s most prominent alternatives to Bohr’s “Copenhagen” interpretation of quantum mechanics.
Genesis of a crisis
The quantum crisis began when German physicist Max Planck proposed the quantization of energy in 1900, as a mathematical trick for calculating the spectrum of radiation from a warm, perfectly absorbing “black body”. Later, in 1905, Einstein suggested taking this idea literally to account for the photoelectric effect, arguing that light consisted of packets or quanta of electromagnetic energy, which we now call photons.
Bohr entered the story in 1912 when, working in the laboratory of Ernest Rutherford in Manchester, he devised a quantum theory of the atom. In Bohr’s picture, the electrons encircling the atomic nucleus (that Rutherford had discovered in 1909) are constrained to specific orbits with quantized energies. The electrons can hop in “quantum jumps” by emitting or absorbing photons with the corresponding energy.
Conflicting views Stalwart physicists Albert Einstein and Niels Bohr had opposing views on quantum fundamentals from early on, which turned into a lifelong scientific argument between the two. (Paul Ehrenfest/Wikimedia Commons)
Bohr had no theoretical justification for this ad hoc assumption, but he showed that, by accepting it, he could predict (more or less) the spectrum of the hydrogen atom. For this work Bohr was awarded the 1922 Nobel Prize for Physics, the same year that Einstein collected the prize for his work on light quanta and the photoelectric effect (he had been awarded it in 1921 but was unable to attend the ceremony).
After establishing an institute of theoretical physics (now the Niels Bohr Institute) in Copenhagen in 1917, Bohr’s mission was to find a true theory of the quantum: a mechanics to replace, at the atomic scale, the classical physics of Isaac Newton that worked at larger scales. It was clear that classical physics did not work at the scale of the atom, although Bohr’s correspondence principle asserted that quantum theory should give the same results as classical physics at a large enough scale.
Mathematical mind Dutch physicist Hendrik Kramers spent 10 years as Niels Bohr’s assistant in Copenhagen. (Wikimedia Commons)
Quantum theory was at the forefront of physics at the time, and so was the most exciting topic for any aspiring young physicist. Three groups stood out as the most desirable places to work for anyone seeking a fundamental mathematical theory to replace the makeshift and sometimes contradictory “old” quantum theory that Bohr had cobbled together: that of Arnold Sommerfeld in Münich, of Max Born in Göttingen, and of Bohr in Copenhagen.
Dutch physicist Hendrik Kramers had hoped to work on his doctorate with Born – but in 1916 the First World War ruled that out, and so he opted instead for Copenhagen, in politically neutral Denmark. There he became Bohr’s assistant for ten years: as was the case with several of Bohr’s students, Kramers did the maths (it was never Bohr’s forte) while Bohr supplied the ideas, philosophy and kudos. Kramers ended up working on an impressive range of problems, from chemical physics to pure mathematics.
Reckless and radical
One of the most vexing question for Bohr and his Copenhagen circle in the early 1920s was how to think about electron orbits in atoms. Try as they might, they couldn’t find a way to make the orbits “fit” with experimental observations of atomic spectra.
Perhaps, in quantum systems like atoms, we have to abandon any attempt to construct a physical picture at all
Bohr and others, including Heisenberg, began to voice a possibility that seemed almost reckless: perhaps, in quantum systems like atoms, we have to abandon any attempt to construct a physical picture at all. Maybe we just can’t think of quantum particles as objects moving along trajectories in space and time.
This struck others, such as Einstein, as desperate, if not crazy. Surely the goal of science had always been to offer a picture of the world in terms of “things happening to objects in space”. What else could there be than that? How could we just give it all up?
But it was worse than that. For one thing, Bohr’s quantum jumps were supposed to happen instantaneously: an electron, say, jumping from one orbit to another in no time at all. In classical physics, everything happens continuously: a particle gets from here to there by moving smoothly across the intervening space, in some finite time. The discontinuities of quantum jumps seemed to some – like Austrian physicist Erwin Schrödinger in Vienna – bordering on the obscene.
Worse still was the fact that while the old quantum theory stipulated the energy of quantum jumps, there was nothing to dictate when they would happen – they simply did. In other words, there was no causal kick that instigated a quantum jump: the electron just seemed to make up its own mind about when to jump. As Heisenberg would later proclaim in his 1927 paper on the uncertainty principle (Zeitschrift für Physik43 172),quantum theory “establishes the final failure of causality”.
Such notions were not the only source of friction between the Copenhagen team and Einstein. Bohr didn’t like light quanta. While they seemed to explain the photoelectric effect, Bohr was convinced that light had to be fundamentally wave-like, so that photons (to use the anachronistic term) were only a way of speaking, not real entities.
To add to the turmoil in 1924, the French physicist Louis de Broglie had, in his doctoral thesis for the Sorbonne, turned the quantum idea on its head by proposing that particles such as electrons might show wave-like behaviour. Einstein had at first considered this too wild, but soon came round to the idea.
Go where the waves take you
In 1924 these virtually heretical ideas were only beginning to surface, but they were creating such a sense of crisis that it seemed anything was possible. In the 1960s, science historian Paul Forman suggested that the feverish atmosphere in physics was part of an even wider cultural current. By rejecting causality and materialism, the German quantum physicists, Forman said, were attempting to align their ideas with a rejection of mechanistic thinking while embracing the irrational – as was the fashion in the philosophical and intellectual circles of the beleaguered Weimar republic. The idea has been hotly debated by historians and philosophers of science – but it was surely in Copenhagen, not Munich or Göttingen, that the most radical attitudes to quantum theory were developing.
Particle pilot In 1923, US physicist John Clark Slater moved to Copenhagen, and suggested the concept of a “virtual field” that spread throughout a quantum system. (Emilio Segrè Visual Archives General Collection/MIT News Office)
Then, just before Christmas in 1923, a new student arrived at Copenhagen. John Clarke Slater, who had a PhD in physics from Harvard, turned up at Bohr’s institute with a bold idea. “You know those difficulties about not knowing whether light is old-fashioned waves or Mr Einstein’s light particles”, he wrote to his family during a spell in Cambridge that November. “I had a really hopeful idea… I have both the waves and the particles, and the particles are sort of carried along by the waves, so that the particles go where the waves take them.” The waves were manifested in a kind of “virtual field” of some kind that spread throughout the system, and they acted to “pilot” the particles.
Bohr was mostly not a fan of Slater’s idea, not least because it retained the light particles that he wished to dispose of. But he liked Slater’s notion of a virtual field that could put one part of a quantum system in touch with others. Together with Slater and Kramers, Bohr prepared a paper in a remarkably short time (especially for him) outlining what became known as the Bohr-Kramers-Slater (BKS) theory. They sent it off to the Philosophical Magazine (where Bohr had published his seminal papers on the quantum atom) at the end of January 1924, and it was published in May (47(281) 785). As was increasingly characteristic of Bohr’s style, it was free of any mathematics (beyond Einstein’s quantum relationship E=hν).
In the BKS picture, an excited atom about to emit light can “communicate continually” with the other atoms around it via the virtual field. The transition, with emission of a light quantum, is then not spontaneous but induced by the virtual field. This mechanism could solve the long-standing question of how an atom “knows” which frequency of light to emit in order to reach another energy level: the virtual field effectively puts the atom “in touch” with all the possible energy states of the system.
The problem was that this meant the emitting atom was in instant communication with its environment all around – which violated the law of causality. Well then, so much the worse for causality: BKS abandoned it. The trio’s theory also violated the conservation of energy and momentum – so they had to go too.
Causality and conservation, abandoned
But wait: hadn’t these conservation laws been proved? In 1923 the American physicist Arthur Compton in Cambridge had shown that when light is scattered by electrons, they exchange energy, and the frequency of the light decreases as it gives up energy to the electrons. The results of Compton’s experiments agreed perfectly with predictions made on the assumptions that light is a stream of quanta (photons) and that their collisions with electrons conserve energy and momentum.
Ah, said BKS, but that’s only true statistically. The quantities are conserved on average, but not in individual collisions. After all, such statistical outcomes were familiar to physicists: that was the basis of the second law of thermodynamics, which presented the inexorable increase in entropy as a statistical phenomenon that need not constrain processes involving single particles.
The radicalism of the BKS paper got a mixed reception. Einstein, perhaps predictably, was dismissive. “Abandonment of causality as a matter of principle should be permitted only in the most extreme emergency”, he wrote. Wolfgang Pauli, who had worked in Copenhagen in 1922–23, confessed to being “completely negative” about the idea. Born and Schrödinger were more favourable.
Geiger agreed, and the duo devised a scheme for detecting both the scattered electron and the scattered photon in separate detectors. If causality and energy conservation were preserved, the detections should be simultaneous; while any delay between them could indicate a violation. As Bothe would later recall “The ‘question to Nature’ which the experiment was designed to answer could therefore be formulated as follows: is it exactly a scatter quantum and a recoil electron that are simultaneously emitted in the elementary process, or is there merely a statistical relationship between the two?” It was incredibly painstaking work to seek such coincident detections using the resources then available. But in April 1925 Geiger and Bothe reported simultaneity within a millisecond – close enough to make a strong case that Compton’s treatment, which assumed energy conservation, was correct. Compton himself, working with Alfred Simon using a cloud chamber, confirmed that energy and momentum were conserved for individual events (Phys. Rev. 26 289).
Revolutionary defeat… singularly important
Bothe was awarded the 1954 Nobel Prize for Physics for the work. He shared it with Born for his work on quantum theory, and Geiger would surely have been a third recipient, if he had not died in 1945. In his Nobel speech, Bothe definitively stated that “the strict validity of the law of the conservation of energy even in the elementary process had been demonstrated, and the ingenious way out of the wave-particle problem discussed by Bohr, Kramers, and Slater was shown to be a blind alley.”
Bohr was gracious in his defeat, writing to a colleague in April 1925 that “It seems… there is nothing else to do than to give our revolutionary efforts as honourable a funeral as possible.” Yet he was soon to have no need of that particular revolution, for just a few months later Heisenberg, who had returned to Göttingen after working with Bohr in Copenhagen for six months, came up the first proper theory of quantum mechanics, later called matrix mechanics.
“In spite of its short lifetime, the BKS theory was singularly important,” says historian of science Helge Kragh, now emeritus professor at the Niels Bohr Institute. “Its radically new approach paved the way for a greater understanding, that methods and concepts of classical physics could not be carried over in a future quantum mechanics.”
The Bothe-Geiger experiment that [the paper] inspired was not just an important milestone in early particle physics. It was also a crucial factor in Heisenberg’s argument [about] the probabilistic character of his matrix mechanics
The BKS paper was thus in a sense merely a mistaken curtain-raiser for the main event. But the Bothe-Geiger experiment that it inspired was not just an important milestone in early particle physics. It was also a crucial factor in Heisenberg’s argument that the probabilistic character of his matrix mechanics (and also of Schrödinger’s 1926 version of quantum mechanics, called wave mechanics) couldn’t be explained away as a statistical expression of our ignorance about the details, as it is in classical statistical mechanics.
Radical approach Despite its swift defeat, the BKS proposal showed how classical concepts could not apply to a quantum reality. (Courtesy: Shutterstock/Vink Fan)
Rather, the probabilities that emerged from Heisenberg’s and Schrödinger’s theories applied to individual events: they were, Heisenberg said, fundamental to the way single particles behave. Schrödinger was never happy with that idea, but today it seems inescapable.
Over the next few years, Bohr and Heisenberg argued that the new quantum mechanics indeed smashed causality and shattered the conventional picture of reality as an objective world of objects moving in space–time with fixed properties. Assisted by Born, Wolfgang Pauli and others, they articulated the “Copenhagen interpretation”, which became the predominant vision of the quantum world for the rest of the century.
Failed connections
Slater wasn’t at all pleased with what became of the idea he took to Copenhagen. Bohr and Kramers had pressured him into accepting their take on it, “without the little lump carried along on the waves”, as he put it in mid-January. “I am willing to let them have their way”, he wrote at the time, but in retrospect he felt very unhappy about his time in Denmark. After the BKS theory was disproved, Bohr wrote to Slater saying “I have a bad conscience in persuading you to our views”.
Slater replied that there was no need for that. But in later life – after he had made a name for himself in solid-state physics – Slater admitted to a great deal of resentment. “I completely failed to make any connection with Bohr”, he said in a 1963 interview with the historian of science Thomas Kuhn. “I fought with them [Bohr and Kramers] so seriously that I’ve never had any respect for those people since. I had a horrible time in Copenhagen.” While most of Bohr’s colleagues and students expressed adulation, Slater’s was a rare dissenting voice.
But Slater might have reasonably felt more aggrieved at what became of his “pilot-wave” idea. Today, that interpretation of quantum theory is generally attributed to de Broglie – who intimated a similar notion in his 1924 thesis, before presenting the theory in more detail at the famous 1927 Solvay Conference – and to American physicist David Bohm, who revitalized the idea in the 1950s. Initially dismissed on both occasions, the de Broglie-Bohm theory has gained advocates in recent years, not least because it can be applied to a classical hydrodynamic analogue, in which oil droplets are steered by waves on an oil surface.
Whether or not it is the right way to think about quantum mechanics, the pilot-wave theory touches on the deep philosophical problems of the field. Can we rescue an objective reality of concrete particles with properties described by hidden variables, as Einstein had advocated, from the fuzzy veil that Bohr and Heisenberg seemed to draw over the quantum world? Perhaps Slater would at least be gratified to know that Bohr has not yet had the last word.
In June 1925 a relatively unknown physics postdoc by the name of Werner Heisenberg developed the basic mathematical framework that would be the basis for the first quantum revolution. Heisenberg, who would later win the Nobel Prize for Physics, famously came up with quantum mechanics on a two-week vacation on the tiny island of Helgoland off the coast of Germany, where he had gone to cure a bad bout of hay fever.
Now, a century later, we are on the cusp of a second quantum revolution, with quantum science and technologies growing rapidly across the globe. According to the State of Quantum 2024 report, a total of 33 countries around the world currently have government initiatives in quantum technology, of which more than 20 have national strategies with large-scale funding. The report estimates that up to $50bn in public cash has already been committed.
It’s a fitting tribute, then, that the United Nations (UN) has chosen 2025 to be the International Year of Quantum Science and Technology (IYQ). They hope that the year will raise global awareness of the impact that quantum physics and its applications have already had on our world. The UN also aims to highlight to the global public the myriad potential future applications of quantum technologies and how they could help tackle universal issues – from climate and clean energy to health and infrastructure – while also addressing the UN’s sustainable development goals.
The Institute of Physics (IOP), which publishes Physics World, is one of the IYQ’s six “founding partners” alongside the German (DPG) and American physical societies (APS), SPIE, Optica and the Chinese Optical Society. “The UNESCO International Year of Quantum is a wonderful opportunity to spread the word about quantum research and technology and the transformational opportunities it is opening up” says Tom Grinyer, chief executive of the IOP. “The Institute of Physics is co-ordinating the UK and Irish elements of the year, which mark the 100th anniversary of the first formulation of quantum mechanics, and we are keen to celebrate the milestone, making sure that as many people as possible get the opportunity to find out more about this fascinating area of science and technology,” he adds.
“IYQ provides the opportunity for societies and organizations around the world to come together in marking both the 100-year history of the field, as well as the longer-term real-world impact that quantum science is certain to have for decades to come,” says Tim Smith, head of portfolio development at IOP Publishing. “Quantum science and technology represents one of the most exciting and rapidly developing areas of science today, encompassing the global physical-sciences community in a way that connects scientific wonder with fundamental research, technological innovation, industry, and funding programmes worldwide.”
Taking shape
The official opening ceremony for IYQ takes place on 4–5 February at the UNESCO headquarters in Paris, France, although several countries, including Germany and India, held their own launches in advance of the main event. Working together, the IOP and IOP Publishing have developed a wide array of quantum resources, talks, conferences, festivals and public-themed events planned as a part of the UK’s celebrations for IYQ.
In late February, meanwhile, the Royal Society – the world’s oldest continuously active learned society – will host a two-day quantum conference. Dubbed “Quantum Information”, it will bring together scientists, industry leaders and public-sector stakeholders to discuss the current challenges involved in quantum computing, networks and sensing systems.
The IOP will use the focus this year gives us to continue to make the case for the investment in research and development, and support for physics skills, which will be crucial if we are to fully unlock the economic and social potential of the quantum sector
With the booming quantum marketplace, it’s no surprise that employers are on the hunt for many skilled physicists to join the workforce. And indeed, there is a significant scarcity of skilled quantum professionals for the many roles across industry and academia. Also, with quantum research advancing everything from software and machine learning to materials science and drug discovery, your skills will be transferable across the board.
If you plan to join the quantum workforce, then choosing the right PhD programme, having the right skills for a specific role and managing risk and reward in the emerging quantum industry are all crucial. There are a number of careers events on the IYQ calendar, to learn more about the many career prospects for physicists in the sector. In April, for example, the University of Bristol’s Quantum Engineering Centre for Doctoral Training is hosting a Careers in Quantum event, while the Economist magazine is hosting its annual Commercialising Quantum conference in May.
There will also be a special quantum careers panel discussion, including top speakers from the UK and the US, as part of our newly launched Physics World Live panel discussions in April. This year’s Physics World Careers 2025 guide has a special quantum focus, and there’ll also be a bumper, quantum-themed issue of thePhysics World Briefing in June. The Physics World quantum channel will be regularly updated throughout the year so you don’t miss a thing.
Read all about it
IOP Publishing’s journals will include specially curated content – from a series of Perspectives articles – personal viewpoints from leading quantum scientists – in Quantum Science and Technology. The journal will also be publishing roadmaps in quantum computing, sensing and communication, as well as focus issues on topics such as quantum machine learning and technologies for quantum gravity and thermodynamics in quantum coherent platforms.
“Going right to the core of IOP Publishing’s own historic coverage we’re excited to be celebrating the IYQ through a year-long programme of articles in Physics World and across our journals, that will hopefully show a wide audience just why everyone should care about quantum science and the people behind it,” says Smith.
In this episode of Physics World Stories, we celebrate the 100th anniversary of Werner Heisenberg’s trip to the North Sea island of Helgoland, where he developed the first formulation of quantum theory. Listen to the podcast as we delve into the latest advances in quantum science and technology with three researchers who will be attending a 6-day workshop on Helgoland in June 2025.
Featuring in the episode are: Nathalie De Leon of Princeton University, Ana Maria Rey from the University of Colorado Boulder, and Jack Harris from Yale University, a member of the programme committee. These experts share their insights on the current state of quantum science and technology: discussing the latest developments in quantum sensing, quantum information and quantum computing.
They also reflect on the significance of attending a conference at a location that is so deeply ingrained in the story of quantum mechanics. Talks at the event will span the science and the history of quantum theory, as well as the nature of scientific revolutions.
Devices like lasers and other semiconductor-based technologies operate on the principles of quantum mechanics, but they only scratch the surface. To fully exploit quantum phenomena, scientists are developing a new generation of quantum-based devices. These devices are advancing rapidly, fuelling what many call the “second quantum revolution”.
One exciting development in this domain is the rise of next-generation energy storage devices known as quantum batteries (QBs). These devices leverage exotic quantum phenomena such as superposition, coherence, correlation and entanglement to store and release energy in ways that conventional batteries cannot. However, practical realization of QBs has its own challenges such as reliance on fragile quantum states and difficulty in operating at room temperature.
A recent theoretical study by Rahul Shastri and colleagues from IIT Gandhinagar, India, in collaboration with researchers at China’s Zhejiang University and the China Academy of Engineering Physics takes significant strides towards understanding how QBs can be charged faster and more efficiently, thereby lowering some of the barriers restricting their use.
How does a QB work?
The difference between charging a QB and charging a mobile phone is that with a QB, both the battery and the charger are quantum systems. Shastri and colleagues focused on two such systems: a harmonic oscillator (HO) and a two-level system. While a two-level system can exist in just two energy states, a harmonic oscillator has an evenly spaced range of energy levels. These systems therefore represent two extremes – one with a discrete, bounded energy range and the other with a more complex, unbounded energy spectrum approaching a continuous limit – making them ideal for exploring the versality of QBs.
In the quantum HO-based setup, a higher-energy HO acts as the charger and a lower-energy one as the battery. When the two are connected, or coupled, energy transfers from the charger to the battery. The two-level system follows the same working principle. Such coupled quantum systems are routinely realized in experiments.
Using decoherence as a tool to improve QB performance
The study’s findings, which are published in npj Quantum Information, are both surprising and promising, illustrating how a phenomenon typically seen as a challenge in quantum systems – decoherence – can become a solution.
The term “decoherence” refers to the process where a quantum system loses its unique quantum properties (such as quantum correlation, coherence and entanglement). The key trigger for decoherence is quantum noise caused by interactions between a quantum system and its environment.
Since no real-world physical system is perfectly isolated, such noise is unavoidable, and even minute amounts of environmental noise can lead to decoherence. Maintaining quantum coherence is thus extremely challenging even in controlled laboratory settings, let alone industrial environments producing large-scale practical devices. For this reason, decoherence represents one of the most significant obstacles in advancing quantum technologies towards practical applications.
Shastri and colleagues, however discovered a way to turn this foe into a friend. “Instead of trying to eliminate these naturally occurring environmental effects, we ask: why not use them to our advantage?” Shashtri says.
The method they developed speeds up the charging process using a technique called controlled dephasing. Dephasing is a form of decoherence that usually involves the gradual loss of quantum coherence, but the researchers found that when managed carefully, it can actually boost the battery’s performance.
Dissipative effects, traditionally seen as a hindrance, can be harnessed to enhance performance
Rahul Shastri
To understand how this works, it’s important to note that at low levels of dephasing, the battery undergoes smooth energy oscillations. Too much dephasing, however, freezes these oscillations in what’s known as the quantum Zeno effect, essentially stalling the energy transfer. But with just the right amount of dephasing, the battery charges faster while maintaining stability. By precisely controlling the dephasing rate, therefore, it becomes possible to strike a balance that significantly improves charging speed while still preserving stability. This balance leads to quicker, more robust charging that could overcome challenges posed by environmental factors.
“Our study shows how dissipative effects, traditionally seen as a hindrance, can be harnessed to enhance performance,” Shastri notes. This opens the door to scalable, robust quantum battery designs, which could be extremely useful for energy management in quantum computing and other quantum-enabled applications.
Implications for scalable quantum technologies
The results of this study are encouraging for the quantum-technology industry. As per Shastri, using dephasing to optimize the charging speed and stability of QBs not only advances fundamental understanding but also addresses practical challenges in quantum energy storage.
“Our proposed method could be tested on existing platforms such as superconducting qubits and NMR systems, where dephasing control is already experimentally feasible,” he says. These platforms offer experimentalists a tangible starting point for verifying the study’s predictions and further refining QB performance.
Experimentalists testing this theory will face challenges. Examples include managing additional decoherence mechanisms like amplitude damping and achieving the ideal balance of controlled dephasing in realistic setups. However, Shastri says that these challenges present valuable opportunities to refine and expand the proposed theoretical model for optimizing QB performance under practical conditions. The second quantum revolution is already underway, and QBs might just be the power source that charges our quantum future.
Our guest in this episode of the Physics World Weekly podcast is the Turkish quantum physicist Mete Atatüre, who heads up the Cavendish Laboratory at the UK’s University of Cambridge.
In a conversation with Physics World’s Katherine Skipper, Atatüre talks about hosting Quantour, the quantum light source that is IYQ’s version of the Olympic torch. He also talks about his group’s research on quantum sensors and quantum networks.
With so much fascinating research going on in quantum science and technology, it’s hard to pick just a handful of highlights. Fun, but hard. Research on entanglement-based imaging and quantum error correction both appear in Physics World’slist of 2024’s top 10 breakthroughs, but beyond that, here are a few other achievements worth remembering as we head into 2025 – the International Year of Quantum Science and Technology.
Quantum sensing
In July, physicists at Germany’s Forschungszentrum Jülich and Korea’s IBS Center for Quantum Nanoscience (QNS) reported that they had fabricated a quantum sensor that can detect the electric and magnetic fields of individual atoms. The sensor consists of a molecule containing an unpaired electron (a molecular spin) that the physicists attached to the tip of a scanning-tunnelling microscope. They then used it to measure the magnetic and electric dipole fields emanating from a single iron atom and a silver dimer on a gold substrate.
Not to be outdone, an international team led by researchers at the University of Melbourne, Australia, announced in August that they had created a quantum sensor that detects magnetic fields in any direction. The new omnidirectional sensor is based on a recently-discovered carbon-based defect in a two-dimensional material, hexagonal boron nitride (hBN). This same material also contains a boron vacancy defect that enables the sensor to detect temperature changes, too.
Quantum communications
One of the challenges with transmitting quantum information is that pretty much any medium you send it through – including high-spec fibre optic cables and even the Earth’s atmosphere – is at least somewhat good at absorbing photons and preventing them from reaching their intended destination.
Networking: Liang Jiang reviews the proposed quantum network using vacuum beam guides, which would have ranges of thousands of kilometers and capacities of 10 trillion qubits per second. (Courtesy: UChicago Pritzker School of Molecular Engineering/John Zich)
In July, a team at the University of Chicago, the California Institute of Technology and Stanford University proposed a novel solution. A continent-scale network of vacuum-sealed tubes, they suggested, could transmit quantum information at rates as high as 1013 qubits per second. This would exceed currently-available quantum channels based on satellites or optical fibres by at least four orders of magnitude. Whether anyone will actually build such a network is, of course, yet to be determined – but you have to admire the ambition behind it.
Quantum fundamentals
Speaking of ambition, this year saw a remarkable flurry of ideas for using quantum devices and quantum principles to study gravity. One innovative proposal involves looking for the gravitational equivalent of the photoelectric effect in a system of resonant bars that have been cooled and tuned to vibrate when they absorb a graviton from an incoming gravitational wave. The idea is that absorbing a graviton would change the quantum state of the column, and this change of state would, in principle, be detectable.
Detecting gravity: Researchers have proposed an experiment that could detect the elusive graviton – a quantum of gravity – using quantum sensing. (Courtesy: Pikovski research group)
Another quantum gravity proposal takes its inspiration from an even older experiment: the Cavendish torsion balance. The quantum version of this 18th-century classic would involve studying the correlations between two torsion pendula placed close together as they rotate back and forth like massive harmonic oscillators. If correlations appear that can’t be accounted for within a classical theory of gravity, this could imply that gravity is not, in fact, classical.
Perhaps the most exciting development in this space, though, is a new experimental technique for measuring the pull of gravity on a micron-scale particle. Objects of this size are just above the limit where quantum effects start to become apparent, and the Leiden and Southampton University researchers who performed the experiment have ideas for how to push their system further towards this exciting regime. Definitely one to keep an eye on.
The best of the rest
It wouldn’t be quantum if it wasn’t at least little bit weird, so here’s a few head-scratchers for you to puzzle over.
Connexion
