In materials science, the yield point represents a critical threshold where a material transitions from elastic to plastic deformation. Below this point, materials like glasses can return to their original shape after stress is removed. Beyond it, however, the deformation becomes permanent, reflecting irreversible changes in the material’s internal structure. Understanding this transition is essential for designing materials that can withstand mechanical stress without failure, an important consideration in fields such as civil engineering, aerospace and electronics.

Despite its importance, the yield point in amorphous materials like glasses has remained difficult to study due to the challenges in precisely controlling and measuring the stress and strain required to trigger it. Traditional mechanical testing methods often lack the resolution needed to observe the subtle atomic-scale changes that occur during yielding.

In this study, the authors present a novel approach using X-ray irradiation to induce yielding in germanium-selenium glasses. This method allows for fine-tuned control over the elasto-plastic transition, enabling the researchers to systematically investigate the onset of plastic deformation. By combining experimental techniques with theoretical modelling, they characterize both the thermodynamic behaviour and the atomic-level structural and dynamical responses of the glasses during and after irradiation.

One of the key findings is that glasses processed through this method become stable against further irradiation, an effect that could be highly beneficial in environments with high radiation exposure, such as space missions or nuclear facilities. This work not only provides new insights into the fundamental physics of yielding in disordered materials but also opens up potential pathways for engineering radiation-resistant glassy materials.

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Theories of glass formation and the glass transition by J S Langer (2014)

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Quantum repeaters are essential components of quantum networks, enabling long-distance entanglement distribution by temporarily storing quantum states. This temporary storage, facilitated by quantum memory, allows synchronization with other network operations and the implementation of error correction protocols, marking a significant advancement over classical repeaters, which merely amplify and retransmit signals. 

Unlike classical systems, quantum repeaters mitigate photon loss, a major source of error in quantum communication. However, widely known quantum repeater designs often suffer from limitations such as the need for high phase stability and an inability to generate strongly entangled states. 

In this work, the authors propose a novel protocol based on post-matching, a technique originally developed in quantum cryptography to verify and secure transmitted information. Their theoretical framework offers new insights into both quantum communication and cryptographic systems, contributing to the advancement of quantum information theory and technology. 

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Explore our Focus on Quantum Entanglement: State of the Art and Open Questions

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Nonlinearity refers to behaviour that deviates from a simple, proportional relationship and cannot be accurately described by linear equations. This concept is fundamental to understanding complex systems across various scientific disciplines, including meteorology, epidemiology, chemistry, and quantum mechanics. 

In the field of quantum optics, achieving nonlinearity at the single-photon level is essential for the development of advanced quantum information protocols. Such nonlinearity enables more precise control over information transmission, facilitates faster and more scalable quantum networks, and enhances the security of quantum communication. 

Rydberg atoms, which are atoms in highly excited states, exhibit strong long-range interactions. These interactions, particularly the Rydberg blockade effect, make them promising candidates for inducing strong nonlinear interactions between photons. However, a key challenge lies in achieving this nonlinearity in a controllable and efficient manner, rather than relying on probabilistic or inefficient methods. 

In this work, the authors introduce a novel approach for precisely engineering Rydberg states to enable continuous tuning of single-photon nonlinearity. This tunability represents a significant advancement, with potential applications spanning fundamental physics and the development of next-generation quantum technologies. 

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Probing quantum correlations in many-body systems: a review of scalable methods by Irénée Frérot, Matteo Fadel and Maciej Lewenstein (2023)

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Supersymmetry is a theoretical framework in which every fermion and boson has a corresponding partner particle, known as a superpartner. These superpartners share the same energy spectrum but differ in their spin properties. The transformations between these particles are governed by mathematical operators called supercharges. Although superpartners have not yet been observed experimentally, their discovery would have significant implications for fundamental physics. 

Twisted bilayer materials, such as graphene and transition metal dichalcogenides, have attracted attention for their unusual electronic and topological properties. In this study, the authors investigate how supersymmetry manifests in these systems by analysing different energy modes associated with twisted bilayers. 

They find that superpartners can exhibit both trivial and nontrivial topological energy bands. Furthermore, they demonstrate that supersymmetry can spontaneously break due to interactions between charged particles, known as Coulomb interactions. 

This research provides new insights into the interplay between topology, symmetry, and interactions in low-dimensional materials, and opens up new possibilities for exploring supersymmetry in condensed matter systems. 

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Desperately seeking supersymmetry (SUSY) by Stuart Raby (2004)

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The Lipkin-Meshkov-Glick model is a theoretical framework used to describe systems of many interacting spins in an external magnetic field. It has been widely applied to study quantum phase transitions, entanglement, and collective spin behaviour. When extended to two modes, the model allows particles to tunnel between two degenerate energy levels, offering insights into quantum systems with multiple states. 

In this study, the authors propose a chiral two mode version of the model using a pair of surface acoustic wave cavities. The chirality in the system preserves the separation between the two modes and prevents them from mixing. By applying specially designed chiral optical drives, the researchers are able to simulate long range asymmetric spin interactions.

This setup enables the simulation of complex quantum phenomena such as time crystal behaviour and ion trap like interactions, without the need for traditional trapping techniques. The work presents a novel approach to engineering and exploring chiral quantum systems using acoustic hybrid platforms.  

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Time crystals: a review by Krzysztof Sacha and Jakub Zakrzewski (2018)

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Developing a unified theory for liquid behaviour has long been a challenge due to the complex interactions between particles and the constantly changing dynamic disorder within liquids. Current approaches rely on empirical equations of state derived from experiments, which are often specific to individual systems and cannot be easily transferred to others. Compared to the well-established thermodynamic models for solids and gases, our understanding of liquids remains significantly underdeveloped. 

In this study, the authors take a foundational step toward creating a general equation of state for liquids based on phonon theory. If successful, such a model could have wide-ranging applications in planetary science, industrial processes, chemical engineering, and condensed matter physics. 

The authors provide a detailed explanation of how they approached this complex problem and apply their theoretical framework to experimental data for argon and nitrogen. The results show strong agreement, suggesting that the model has the potential for broad applicability. 

This work represents a significant advance in the theoretical understanding of liquids and opens the door to a more unified and transferable approach to liquid thermodynamics. 

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Collective modes and thermodynamics of the liquid state by K Trachenko and V V Brazhkin (2015)

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One of the key challenges in building scalable quantum computers is managing noise during operations in order to improve accuracy. Decoherence, which arises from systematic errors and environmental interactions, disrupts quantum information and limits performance. 

Several strategies exist to reduce decoherence. One approach is dynamical decoupling, which averages out noise through carefully timed control pulses. Another is quantum error correction, which detects and corrects faults in a quantum computation. In this study, the authors explore a third approach by leveraging the symmetry of quantum systems to create decoherence-free subspaces. These subspaces isolate quantum information from environmental noise. 

The authors investigate how these decoherence-free subspaces can be integrated with existing error protection techniques. They construct a logical qubit within a decoherence-free subspace using a specially designed pulse sequence. When combined with dynamical decoupling, this method improves the fidelity of quantum states by up to 23% compared to physical qubits. 

This research presents a practical and effective way to incorporate decoherence-free subspaces into quantum error management, offering a promising path toward more reliable quantum computing. 

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Quantum algorithms for scientific computing by R Au-Yeung, B Camino, O Rathore and V Kendon (2024)

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Time crystals are an intriguing state of matter in which a system exhibits periodic motion even in its lowest energy state. This challenges conventional expectations in physics. These systems arise when time translation symmetry is broken, a principle that normally ensures physical laws remain unchanged over time. 

Unlike ordinary systems, time crystals can exhibit persistent oscillations without absorbing net energy over time. This makes them a subject of great interest in condensed matter physics and a promising candidate for future technologies such as quantum computing, sensing, superconductivity, and energy storage. 

Time crystals can be classified as either discrete or continuous. An external periodic force drives discrete time crystals, while continuous time crystals emerge from the collective and self-sustained oscillations of particles. 

In this study, the authors demonstrate a method for converting a continuous time crystal into a discrete one using a process known as subharmonic injection locking. This technique synchronizes the system’s oscillations with a fraction of the driving frequency. It enables the first observation of a transition between continuous and discrete time crystal states in a system that is not in equilibrium. 

This research provides new insights into the behaviour of time crystals and introduces a powerful approach for controlling and manipulating these unusual phases of matter. 

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Time crystals: a review by Krzysztof Sacha and Jakub Zakrzewski (2018)

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