Articles in 2023

Non-reciprocal electronic transport in a superconducting device is known as superconducting diode effect, which has potential for dissipationless electronics and computing. Previously, conventional superconductors have been used. Here, authors present their findings of such an effect in devices based on an unconventional superconductor Sr2RuO4 that may break time reversal symmetry.

The authors provide an application of dynamical mean-field theory to the spin dynamics in strongly correlated electron systems showing the impact of dynamic electron-electron self-energies and vertex functions on the Larmor mode and damping processes. The results show the superior nature of the methodology against simpler random-phase approximation techniques.

Non-Hermitian physics expands the range of exotic features that can be explored in non-trivial topological systems and exceptional points play a prominent role. Here, the authors report a topological classification of the intersections of exceptional surfaces and predicted topologically protected edge states that arise from the intersections.

Fractionalisation is a key feature of quantum mechanics and one of the most well-known examples in a condensed-matter system is the fractional quantum Hall effect. Here, the authors consider spin fractionalisation in a cluster-based Haldane state of a spin-1/2 Heisenberg triangular tube theoretically showing that the spin-1/2 magnetisation can be further fractionalised to an approximate 1/4 spin under an applied magnetic field.

Superconducting spintronics has the potential to enhance device functionality by realising spin polarised supercurrents with greater coherence and reduced dissipation. Here, using ferromagnetic resonance, the authors investigate the temperature dependence of the Gilbert damping for the Fe layer of Nb/Fe/Nb and Nb/Cr/Fe/Cr/Nb stacks and the impact superconducting spin triplets have on the spin pumping behaviour.

Laser-plasma electron accelerators are ultracompact and come with an embedded betatron X-ray source with small source size and ultrashort pulse length. The authors combine the edge illumination-beam tracking technique with a compact plasma X-ray source and present a demonstration of multimodal imaging down to the femtosecond timescale.

Chimera states have a close relationship with brain functionality but how to understand them directly from brain functional networks is challenging. Here, using the method of eigenmode analysis, the authors report a condensation phenomenon of all eigenmodes of brain functional networks and show that the chimera states represent the condensation on lower eigenmodes.

The authors use reinforcement learning (RL), an important algorithm in machine learning, to optimize nonequilibrium quantum thermodynamics. They find the optimized evolution of the state with higher fidelity and less consumption of entropy production as well as less work cost than in the case of free evolution, highlighting the potential of RL strategies.

The interplay between ferromagnetism and superconductivity plays an important role in trying to understand the mechanisms of superconductivity in iron-based pnictides. Here, the authors investigate a phenomenon called intertype superconductivity which appears due to a crossover from type II to type I between the superconducting transition temperature and magnetic ordering one.

The task of mapping solid-state spin-orbit coupling (SOC) into photonic systems has sparked intense research efforts. The authors propose a unified theory to study SOC in photonic and classical wave systems, that is validated numerically and through ad hoc experiments with Bloch-type photonic skyrmions, showing excellent agreement between the two.

Nonsequential multiple ionization is believed to be suppressed in circularly polarized fields, as the released electron spirals away from the parent ion. The authors challenge this belief, finding that the released outermost electron is stabilized after dislodging other inner-shell electrons, leading to the emergence of a transient hollow atom.

Spintronic emitters based on magnetic heterostructures are promising THz sources, yet their application is limited by relatively low intensities. The authors enhance the intensity of THz emitters by introducing MgO impurities into Pt, and relate the enhanced emission to the combined effect of bulk spin hall angle and interfacial skew scattering.

The pursuit of a target in a turbulent flow is a formidable task due to the chaotic nature of the trajectory of the targets, as the pursuer suffers of limited speed and maneuverability. The authors optimize the pursuit trajectory in these dire conditions via an optimal control strategy applied to the pursuit of a Lagrangian target.

Topoelectrical circuits are suitable to realise and study a range of exotic physical phenomenon that may be less straightforward to investigate using other platforms. Here, the authors demonstrate topologically protected edge states using integrated circuits based on a Kitaev topological superconductor model.

The complexity of many-body sign structures is one of the major issues that severely limits the applicability of variational and quantum Monte Carlo algorithms for calculating properties of quantum many-body systems. Here, the authors propose a method to find the sign structure of frustrated quantum spin systems based on the premise that the amplitude and signs of the wave function can be separated and the latter reconstructed using combinatorial optimization.

Some ultrastable glasses films had been observed to lack the “universal” low-temperature anomalies of glasses, but the role of their anisotropy was unclear. In this article, by measuring the specific heat of an organic material in different glassy states at low temperatures, it is shown that the suppression of two-level systems in glasses depends on the degree of stability, not on anisotropy.

High-dimensional quantum entanglement is generated via a singly filtered biphoton frequency comb, with energy-time entanglement witnessed for both between time bins and frequency bins. Entanglement distribution of such high dimensional entangled state is verified with high quality and provides a testbed for high-dimensional quantum key distribution.