Research articles

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.

The authors employ topolectric circuits to realize a non-Hermitian topological Hopf bundle state of matter, which allows them to observe the emergence of phases that are unique to non-Hermitian systems. The proposed non-Hermitian Hopf bundle platform and visualization methodology pave the way for designing new topologically robust non-Hermitian phases of matter.

A wide range of topological phases have generated interest, notably within the context of magnetic semimetals, where specific symmetries tied to magnetic orders ensure the preservation of distinct topological states. By introducing staggered rotations, the authors show a route to manipulate vector chirality, facilitating a topological phase transition and tunable anomalous Hall conductivity in the noncollinear chiral antiferromagnet Mn₃Sn.

Quantum communication networks are expected to exceed the performance of communications systems based on classical physics in terms of security and communication efficiency and contribute towards the formation of quantum internet. Here, the authors present a model of complex quantum communication networks based on quantum Ising spins where entangled clusters serve as efficient communication channels.

The ever-expanding field of gravitational wave science calls for controlled laboratory experiments on dynamic gravitation to provide insights and more precise measurements of gravity. The authors propose, model, and experimentally realize a system using two rotating bars as transmitter and a bending beam resonator as detector, finding that the near field gravitational energy transfer that creates detector amplitudes of up to 100 nm/s is 10 to the power of 25 times higher than what would be expected from gravitational waves emitted from an equivalent quadrupole gravitational wave generator.

Adiabatic quantum annealers offer a promising path to establish an edge over classical computation, even though the demonstration of an advantage is still open. In this paper, the authors employ Quantum RBMs on Adiabatic quantum annealers, finding orders-of-magnitude speed-up compared to classical computers on real-world cybersecurity tasks for negative phase sampling.

Quantum circuits are constructed from various superconducting components such as qubits and quantum logic gates and each come with their own challenges in terms of efficient operation. Here, the authors investigate the effects of magnetic field penetration on superconducting coplanar waveguide resonators and suggest ways to improve their magnetic resilience.

A recurring theme in physics has been the discovery of distinctive phases of matter. Here, the authors propose a general recipe for constructing projective mirror symmetry and report an experimental realization of mirror Chern insulators in spinless systems.

The valley Hall effect offers an additional degree of freedom in 2D materials than can have implications for optoelectronic-based applications but measuring and controlling the effect is challenging. Here, the authors offer an approach to measure the valley Hall response using strain to induce variations in the particle density from which information on the Hall conductivity can be taken.

Mode-pairing quantum key distribution (MP-QKD) is a potential protocol. Here the authors analyze the finite-key effect for the MPQKD protocol with rigorous security proof against general attacks. And they propose a six-state MP-QKD protocol and analyze its finite key effect.

The time correlation between primary electrons and the secondary particles in electron microscopies encloses information of the whole interaction and excitation dynamics. The authors introduce time-correlated electron and photon counting microscopy that acts as a universal analysis approach for photon generation processes and arbitrary emitters.