Qubits – the building blocks of quantum computers – are plagued with a seemingly unsurmountable dilemma. If they’re fast, they aren’t robust. And if they’re robust, they aren’t fast. Both qualities are important, because all potentially useful quantum algorithms rely on being able to perform many manipulations on a qubit before its state decays. But whereas faster qubits are typically realized by strongly coupling them to the external environment, enabling them to interact more strongly with the driving field, robust qubits with long coherence times are typically achieved by isolating them from their environment.

These seemingly contradictory requirements made simultaneously fast and robust qubits an unsolved challenge – until now. In an article published in Nature Communications, a team of physicists led by Dominik Zumbühl from the University of Basel, Switzerland show that it is, in fact, possible to increase both the coherence time and operational speed of a qubit, demonstrating a pathway out of this long-standing impasse.

The magic ingredient

The key ingredient driving this discovery is something called the direct Rashba spin-orbit interaction. The best-known example of spin-orbit interaction comes from atomic physics. Consider a hydrogen atom, in which a single electron revolves around a single proton in the nucleus. During this orbital motion, the electron interacts with the static electric field generated by the positively charged nucleus. The electron in turn experiences an effective magnetic field that couples to the electron’s intrinsic magnetic moment, or spin. This coupling of the electron’s orbital motion to its spin is called spin-orbit (SO) interaction.

Aided by collaborators at the University of Oxford, UK and TU Eindhoven in the Netherlands, Zumbühl and colleagues chose to replace this simple SO interaction with a far more complex landscape of electrostatic potential generated by a 10-nanometer-thick germanium wire coated with a thin silicon shell. By removing a single electron from this wire, they create states known as holes that can be used as qubits, with quantum information being encoded in the hole’s spin.

Importantly, the underlying crystal structure of the silicon-coated germanium wire constrains these holes to discrete energy levels called bands. “If you were to mathematically model a low-level hole residing in one of these bands using perturbation theory – a commonly applied method in which more remote bands are treated as corrections to the ground state – you would find a term that looks structurally similar to the spin–orbit interaction known from atomic physics,” explains Miguel Carballido, who conducted the work during his PhD at Basel, and is now a senior research associate at the University of New South Wales’ School of Electrical Engineering and Telecommunications in Sydney, Australia.

By encoding the quantum states in these energy levels, the spin-orbit interaction can be used to drive the hole-qubit between its two spin states. What makes this interaction special is that it can be tuned using an external electric field. Thus, by applying a stronger electric field, the interaction can be strengthened – resulting in faster qubit manipulation.

Reaching a plateau

This ability to make a qubit faster by tuning an external parameter isn’t new. The difference is that whereas in other approaches, a stronger interaction also means higher sensitivity to fluctuations in the driving field, the Basel researchers found a way around this problem. As they increase the electric field, the spin-orbit interaction increases up to a certain point. Beyond this point, any further increase in the electric field will cause the hole to remain stuck within a low energy band. This restricts the hole’s ability to interact with other bands to change its spin, causing the SO interaction strength to drop.

By tuning the electric field to this peak, they can therefore operate in a “plateau” region where the SO interaction is the strongest, but the sensitivity to noise is the lowest. This leads to high coherence times (see figure), meaning that the qubit remains in the desired quantum state for longer. By reaching this plateau, where the qubit is both fast and robust, the researchers demonstrate the ability to operate their device in the “compromise-free” regime.

So, is quantum computing now a solved problem? The researchers’ answer is “not yet”, as there are still many challenges to overcome. “A lot of the heavy lifting is being done by the quasi 1D system provided by the nanowire,” remarks Carballido, “but this also limits scalability.” He also notes that the success of the experiment depends on being able to fabricate each qubit device very precisely, and doing this reproducibly remains a challenge.

The post Can fast qubits also be robust? appeared first on Physics World.

Victoria, Canada / Seoul, South Korea – November 27th, 2025 – Pacific Geomatics Limited (PacGeo), a Canadian satellite imagery distributor, today announced a strategic partnership with SI Analytics (SIA), a […]

The post Pacific Geomatics and SI Analytics Announce Strategic Partnership to Deliver Super-Resolution Capabilities Across Canada appeared first on SpaceNews.

ESA wrapped up the first day of a critical ministerial conference sounding upbeat about progress in securing funding for the next three years, despite a few warning signs.

The post ESA on ‘good track’ to secure funding despite notes of caution appeared first on SpaceNews.

Learn more about the fossilized trackway, which provides important insights into the movement of massive dinosaurs.

Learn more about a new cancer blood test that increases cancer detection multifold and what its limitations are.

Learn what caused a major population crash in the Maya civilization, driving several cities to fall into ruin.

Learn how early reptiles began building the visual and brain skills needed for flight long before takeoff.

Specialized appendage responds to female sex hormones, allowing males to find sex organs in the dark

Government pledges to more than triple research spending by 2030

Technology that uses a less known sensory system to substitute for olfaction could one day help anosmic people detect some odors

Learn how the brain sorts fleeting moments from lasting memories using a multi-stage molecular process.

SmartSky Networks does not plan to seek an injunction to block Gogo’s 5G air-to-ground rollout across the United States, despite prevailing in a patent-infringement lawsuit tied to the technology.

The post SmartSky won’t block Gogo 5G air-to-ground network despite legal win appeared first on SpaceNews.

Learn how several working groups with their own carving techniques built the iconic moai of Easter Island.

BREMEN, Germany –  As the 23 member states of the European Space Agency meet this week to decide its budget for the next three years, its three major contributors – Germany, France and Italy – are signaling they will heavily support the agency. Yet even as ESA leaders push for unity, officials from those countries […]

The post Diverging priorities shape opening day of ESA Ministerial 2025 appeared first on SpaceNews.

Learn more about the genetics of the vampire squid — a strange species whose genome suggests that modern octopuses, squids, and cuttlefish evolved from a squid-like ancient ancestor.

Unassigned bones from Ethiopia, combined with teeth and jaw finds, show how two ancient hominin species thrived on different diets and ways of moving 3.4 million years ago.

Identity of the toe bones and other fossils could shake up the human family tree

DNA recovered from people buried at the site reveals surprises

Ever wanted to pick the brains of the reporters who power SpaceNews? Join us Friday, Dec. 5 for your chance to engage with our newsroom team during a subscriber-only live […]

The post Dec. 5: AMA with the SpaceNews editorial team appeared first on SpaceNews.

In the early universe, moments after the Big Bang and cosmic inflation, clusters of exotic, massive particles could have collapsed to form bizarre objects called cannibal stars and boson stars. In turn, these could have then collapsed to form primordial black holes – all before the first elements were able to form.

This curious chain of events is predicted by a new model proposed by a trio of scientists at SISSA, the International School for Advanced Studies in Trieste, Italy.

Their proposal involves a hypothetical moment in the early universe called the early matter-dominated (EMD) epoch. This would have lasted only a few seconds after the Big Bang, but could have been dominated by exotic particles, such as the massive, supersymmetric particles predicted by string theory.

“There are no observations that hint at the existence of an EMD epoch – yet!” says SISSA’s Pranjal Ralegankar. “But many cosmologists are hoping that an EMD phase occurred because it is quite natural in many models.”

Some models of the early universe predict the formation of primordial black holes from quantum fluctuations in the inflationary field. Now, Ralegankar and his colleagues, Daniele Perri and Takeshi Kobayashi propose a new and more natural pathway for forming primordial holes via an EMD epoch.

They postulate that in the first second of existence when the universe was small and incredibly hot, exotic massive particles emerged and clustered in dense haloes. The SISSA physicists propose that the haloes then collapsed into hypothetical objects called cannibal stars and boson stars.

Cannibal stars are powered by particles annihilating each other, which would have allowed the objects to resist further gravitational collapse for a few seconds. However, they would not have produced light like normal stars.

“The particles in a cannibal star can only talk to each other, which is why they are forced to annihilate each other to counter the immense pressure from gravity,” Ralegankar tells Physics World. “They are immensely hot, simply because the particles that we consider are so massive. The temperature of our cannibal stars can range from a few GeV to on the order of 10¹⁰ GeV. For comparison, the Sun is on the order of keV.”

Boson stars, meanwhile, would be made from pure a Bose–Einstein condensate, which is a state of matter whereby the individual particles quantum mechanically act as one.

Both the cannibal stars and boson stars would exist within larger haloes that would quickly collapse to form primordial black holes with masses about the same as asteroids (about 10¹⁴–10¹⁹ kg). All of this could have taken place just 10 s after the Big Bang.

Dark matter possibility

Ralegankar, Perri and Kobayashi point out that the total mass of primordial black holes that their model produces matches the amount of dark matter in the universe.

“Current observations rule out black holes to be dark matter, except in the asteroid-mass range,” says Ralegankar. “We showed that our models can produce black holes in that mass range.”

Richard Massey, who is a dark-matter researcher at Durham University in the UK, agrees that microlensing observations by projects such as the Optical Gravitational Lensing Experiment (OGLE) have ruled out a population of black holes with planetary masses, but not asteroid masses. However, Massey is doubtful that these black holes could make up dark matter.

“It would be pretty contrived for them to make up a large fraction of what we call dark matter,” he says. “It’s possible that dark matter could be these primordial black holes, but they’d need to have been created with the same mass no matter where they were and whatever environment they were in, and that mass would have to be tuned to evade current experimental evidence.”

In the coming years, upgrades to OGLE and the launch of NASA’s Roman Space Telescope should finally provide sensitivity to microlensing events produced by objects in the asteroid mass range, allowing researchers to settle the matter.

It is also possible that cannibal and boson stars exist today, produced by collapsing haloes of dark matter. But unlike those proposed for the early universe, modern cannibal and boson stars would be stable and long-lasting.

“Much work has already been done for boson stars from dark matter, and we are simply suggesting that future studies should also think about the possibility of cannibal stars from dark matter,” explains Ralegankar. “Gravitational lensing would be one way to search for them, and depending on models, maybe also gamma rays from dark-matter annihilation.”

The research is described in Physical Review D.

The post Did cannibal stars and boson stars populate the early universe? appeared first on Physics World.

The EPA is prioritizing review of new chemicals to be used in data centers. Experts say this could lead to the fast approval of new types of forever chemicals—with limited oversight.

NASA has selected Northrop Grumman to provide cargo delivery services to the International Space Station once a spacecraft designed to deorbit the station is installed.

The post Northrop Grumman selected to provide cargo services for final phase of ISS appeared first on SpaceNews.

The deliberate targeting of scientists in recent years has become one of the most disturbing, and overlooked, developments in modern conflict. In particular, Iranian physicists and engineers have been singled out for almost two decades, with sometimes fatal consequences. In 2007 Ardeshir Hosseinpour, a nuclear physicist at Shiraz University, died in mysterious circumstances that were widely attributed to poisoning or radioactive exposure.

Over the following years, at least five more Iranian researchers have been killed. They include particle physicist Masoud Ali-Mohammadi, who was Iran’s representative at the Synchrotron-light for Experimental Science and Applications in the Middle East project. Known as SESAME, it is the only scientific project in the Middle East where Iran and Israel collaborate.

Others to have died include nuclear engineer Majid Shahriari, another Iranian representative at SESAME, and nuclear physicist Mohsen Fakhrizadeh, who were both killed by bombing or gunfire in Tehran. These attacks were never formally acknowledged, nor were they condemned by international scientific institutions. The message, however, was implicit: scientists in politically sensitive fields could be treated as strategic targets, even far from battlefields.

What began as covert killings of individual researchers has now escalated, dangerously, into open military strikes on academic communities. Israeli airstrikes on residential areas in Tehran and Isfahan during the 12-day conflict between the two countries in June led to at least 14 Iranian scientists and engineers and members of their family being killed. The scientists worked in areas such as materials science, aerospace engineering and laser physics. I believe this shift, from covert assassinations to mass casualties, crossed a line. It treats scientists as enemy combatants simply because of their expertise.

The assassinations of scientists are not just isolated tragedies; they are a direct assault on the global commons of knowledge, corroding both international law and international science. Unless the world responds, I believe the precedent being set will endanger scientists everywhere and undermine the principle that knowledge belongs to humanity, not the battlefield.

Drawing a red line

International humanitarian law is clear: civilians, including academics, must be protected. Targeting scientists based solely on their professional expertise undermines the Geneva Convention and erodes the civilian–military distinction at the heart of international law.

Iran, whatever its politics, remains a member of the Nuclear Non-Proliferation Treaty and the International Atomic Energy Agency. Its scientists are entitled under international law to conduct peaceful research in medicine, energy and industry. Their work is no more inherently criminal than research that other countries carry out in artificial intelligence (AI), quantum technology or genetics.

If we normalize the preemptive assassination of scientists, what stops global rivals from targeting, say, AI researchers in Silicon Valley, quantum physicists in Beijing or geneticists in Berlin? Once knowledge itself becomes a liability, no researcher is safe. Equally troubling is the silence of the international scientific community with organizations such as the UN, UNESCO and the European Research Council as well as leading national academies having not condemned these killings, past or present.

Silence is not neutral. It legitimizes the treatment of scientists as military assets. It discourages international collaboration in sensitive but essential research and it creates fear among younger researchers, who may abandon high-impact fields to avoid risk. Science is built on openness and exchange, and when researchers are murdered for their expertise, the very idea of science as a shared human enterprise is undermined.

The assassinations are not solely Iran’s loss. The scientists killed were part of a global community; collaborators and colleagues in the pursuit of knowledge. Their deaths should alarm every nation and every institution that depends on research to confront global challenges, from climate change to pandemics.

I believe that international scientific organizations should act. At a minimum, they should publicly condemn the assassination of scientists and their families; support independent investigations under international law; as well as advocate for explicit protections for scientists and academic facilities in conflict zones.

Importantly, voices within Israel’s own scientific community can play a critical role too. Israeli academics, deeply committed to collaboration and academic freedom, understand the costs of blurring the boundary between science and war. Solidarity cannot be selective.

Recent events are a test case for the future of global science. If the international community tolerates the targeting of scientists, it sets a dangerous precedent that others will follow. What appears today as a regional assault on scientists from the Global South could tomorrow endanger researchers in China, Europe, Russia or the US.

Science without borders can only exist if scientists are recognized and protected as civilians without borders. That principle is now under direct threat and the world must draw a red line – killing scientists for their expertise is unacceptable. To ignore these attacks is to invite a future in which knowledge itself becomes a weapon, and the people who create it expendable. That is a world no-one should accept.

The post Academic assassinations are a threat to global science appeared first on Physics World.

After a high-profile malfunction left two astronauts stranded on the International Space Station, NASA is requiring rigorous testing before humans get back on board.