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)

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)

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)

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)

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)

A strange metal is a type of material that exhibits unusual electrical properties, challenging our conventional understanding of how metals conduct electricity.

In these metals, electrons lose their individual identities, acting collectively in a soup, in which all particles are connected through quantum entanglement. 

Prof. Chung, National Yang Ming Chiao Tung University

Many so-called high temperature superconductors, such as doped cuprates, transition from their superconducting state to a strange metal state as they increase in temperature beyond a critical point. (Note that ‘high’ in this context means above −196.2 °C, the boiling point of liquid nitrogen!)

It has long been thought that revealing the mystery of the strange metal state is the key to understanding the mechanism for high-temperature conductivity. This could lead to understanding what would be required to make a truly room temperature superconductor.

In this new paper, the researchers used a cutting-edge theoretical framework to provide a microscopic description of the strange metal state, focusing on how local charge fluctuations near a critical transition, play a key role.

Their theoretical predictions for quantities such as the specific heat coefficient and the single-particle spectral function in the strange metal state agree well with experimental observations.

This work therefore brings us much closer to understanding how superconductivity emerges from the strange metal state in the cuprates – an open problem in condensed matter physics since the 1990s.

Most complex carbon molecules – such as those necessary for life – actually exist in two forms. The normal one and its mirror image. The left-handed version and the right-handed version.

Despite containing the same atoms, these two molecules usually have vastly different properties. For example, one might be used as a therapeutic drug, while the other could be inactive or even harmful.

Separating them is therefore very important for several reasons, particularly in the fields of chemistry, biology, and medicine. However, due to the lack of differences in the physical properties of the two molecules, this is usually quite difficult.

When any molecule is exposed to light, its quantum energy levels are split apart because of the interaction.

In this paper, the team found that when this light is circularly polarised, the splitting is different for the two mirrored molecules. They also went on to find that this effect led to different photochemical reactions for each molecule, further providing ways to distinguish them.

These effects could then be used as new methods for separating these mirrored molecules in medicine and beyond.

Ever since graphene was first studied in the 2000s, scientists have been interested 2D materials because of their new and interesting electrical and optical properties as well as their potential applications in superconductivity, magnetism and next generation electronics.

In recent years, a new family of these materials has emerged, with a strange new feature: correlated flat bands. Electrons in these bands have the same energy regardless of their movement or position within the material.

In this new work, the researchers used cutting edge theory and computer simulation techniques to understand these types of materials with and predict their properties. In particular, they focused on the interplay between smectic order and topological order.

The term smectic is used when talking about liquid crystals (that’s the same liquid crystal that you find in an LCD TV) . The word just means a state in which the particles are oriented in parallel and arranged in well-defined planes. It’s heavily influenced by the individual particles’ shape structure and charge.

Topological order on other hand is a global type of particle arrangement and is caused by the collective entanglement of all the particles in a system as a whole. It’s very much a quantum phenomenon, and is therefore sometimes unintuitive, strange, and complex.

Usually, these two different types of order are seen to compete with each other, but this study looks at what happens if they exist together.

Based on the results, the team expects several new phase transitions to occur in these systems.

Ultimately, experiments will be required to confirm their predictions. What’s for certain though, is that given how comprehensive this work is, the experimentalists now have a lot of work to do.

Shear-induced structural transitions happen when the structure of a material changes due to the application of force. It’s a phenomenon observed in various systems, including metals like aluminium and iron, molecular crystals such as ice and quartz, and even the Earth’s mantle.

A better understanding of how it works could lead to an improvement in the processing and fabrication of materials with more control on defect formation.

Measuring microscopic processes like this is usually challenging because electron microscopy cannot resolve individual atoms’ motions in bulk solids, and the strong shear force makes things especially difficult.

Here, the researchers used colloidal crystals, allowing them to observe transitions at the single-particle level. As a soft material (one that can easily be deformed), colloid crystals are particularly well-suited for this type of study.

They found that under certain conditions, a liquid layer formed around the growing new crystal structure. This phenomenon is known as “virtual melting” because it occurs well below the effective melting temperature. This liquid layer facilitates the transition by reducing the strain energy at the interface between the old and new crystal structures.

Virtual melting has been proposed in theory and simulation, but had never been directly observed in experiments before. The team’s results not only represent the first experimental observation of this process but also help us to better understand under what circumstances it takes place.

The study has potential applications across various fields, including metallurgy, materials science, and geophysics. The concept of virtual melting could also provide new a new way of thinking about stress relaxation and phase transitions in other systems.

Protons and neutrons in atomic nuclei are themselves made up of fundamental particles known as quarks. These quarks are held together by the strong interaction via force carriers called gluons.

When heavy atomic nuclei collide at high energies close to the speed of light, these constituent particles can break free from each other. The resulting substance, called a quark–gluon plasma, exhibits collective flowlike behaviour much like an everyday liquid.  Unlike a normal viscous liquid however, these near-perfect fluids lose very little energy as they flow.

Researchers are very interested quark–gluon plasmas because they filled the entire Universe just after the Big Bang before matter as we know it was created.

The CMS Collaboration of scientists at CERN routinely create this state of matter for a very brief moment by colliding large nuclei with each other.  In this paper, the researchers used sound waves as a way of understanding the plasma’s fundamental properties.

Sound is a longitudinal wave that produces compressions and rarefactions of matter in the same direction as its movement. The speed of these waves depends on the medium’s properties, such as its density and viscosity. It can, therefore, be used as a probe of the medium.

The team were able to show that the speed of sound in their quark–gluon plasma was nearly half the speed of light – a measurement they made with record precision compared to previous studies.

The results will help test our theories of the fundamental forces that hold matter together, allowing us to better understand matter in the very early Universe as well as future results at particle colliders.