A new Collection by the Physical Review journals celebrates the 50th anniversary of the discovery of asymptotic freedom in quantum chromodynamics (QCD)—the theoretical basis for the strong force of nature that binds quarks and gluons into hadrons.

The American Physical Society (APS) is pleased to announce that it will begin sponsoring Astrobites, a daily astrophysical literature journal written by graduate students in astronomy. This mutually beneficial collaboration aims to enhance the dissemination of research, educational resources, and career insights in the field of astronomy and astrophysics.

Reversible to irreversible (R-IR) transitions have been found in a wide variety of both soft and hard matter periodically driven collectively interacting systems that, after a certain number of driving cycles, organize into either a reversible state where the particle trajectories repeat during every or every few cycles or into a chaotic motion state. An overview of R-IR transitions including recent advances in the field is followed by a discussion of how the general framework of R-IR transitions could be applied to a much broader class of nonequilibrium systems in which periodic driving occurs, including not only soft and hard condensed matter systems, but also astrophysics, biological systems, and social systems.

The supercurrent noise in the equilibrium state induced by thermal fluctuations of the phase-coherent Andreev bound states in a mesoscopic superconductor-normal ring is directly observed and the fluctuation-dissipation relation in such a system is experimentally confirmed.

Not all quantum chaos scrambles quantum information: While the Sachdev-Ye-Kitaev model does, typical chaotic spin chains do not.

The first-principles calculation of a quasiparticle band structure on actual quantum computers is demonstrated. This is achieved by hybrid quantum-classical algorithms in conjunction with qubit-reduction and error-mitigation techniques.

The full quantum geometric tensor (QGT) is experimentally obtained for a plasmonic lattice. The quantum metric and the Berry curvature, related to the real and imaginary parts of the QGT, respectively, are found to be nonzero along the diagonals of the Brillouin zone, even for a trivial square lattice. While the quantum metric emerges from the interplay of polarization and the mode structure, the origin of the Berry curvature is purely non-Hermitian due to the system losses.

The phenomenon of epidemic criticality in temporal networks is remarkably complex due to the competition between the network correlation effect (the persistence of links in the network) and the dynamic correlation effect (the tendency of infected nodes to group together).

The onset of athermal jamming is argued to be a critical phenomenon describable by a mean-field theory in physical dimensions. By elucidating the scaling behavior of jammed systems subjected to active forces and thermal fluctuations in the vicinity of the jamming onset, it’s shown that the physics of active jamming remains mean-field-like in contrast with active systems in which anomalous scaling behavior is the norm.

A direct construction for the projected entangled pair states representation of states that admit descriptions in terms of exponentially localized Wannier functions is proposed. The construction involves first obtaining a tree tensor network construction for subregions, then stacking the tree tensor networks, and finally compressing local tensors successively.

In a size-disperse granular shear flow, particles too small to be trapped in the absence of shear percolate more slowly with increasing shear rate because of their increased velocity fluctuations, while small particles large enough to be trapped at zero shear are mobilized with increasing shear rate but eventually reach a maximum percolation speed and then slow down because of velocity fluctuations

The behavior of an impurity in a trapped Bose gas at finite temperature is studied. It is observed that the impurity is expelled to the edge of the bath at low temperatures, while it remains at the center of the trap as temperature increases.

Work fluctuations of a qubit undergoing dynamics governed by a non-Hermitian Hamiltonian are investigated, demonstrating the validity of the Jarzynski equality even in parameter regimes corresponding to purely imaginary energy eigenvalues. The role of parity-time symmetry in determining the applicability of the second law of thermodynamics to non-Hermitian systems is highlighted, contributing to the understanding of nonequilibrium quantum thermodynamics in open systems.

Oscillations of localized states of Bose-Einstein condensates in tilted quasiperiodic optical lattices are described. The dynamics is driven by quasiresonances assisted by simultaneous tunneling of atoms in coordinate and energy spaces. The selection rule determining resonant states is established.

Atomic Bloch oscillations in an optical lattice transfer momentum from photons to atoms and can be used within atom interferometers to enhance their force sensing capabilities. The quantum phase accrued during such momentum transfer is measured for up to 100 photons and found to be consistent with fully coherent evolution.

Based on a generalized nonlinear paraconductivity framework with microscopically derived Ginzburg-Landau coefficients, nonreciprocal charge transport is theoretically established as a key indicator of helical superconductivity.

Based on discrete-element numerical simulations of wet granular samples, this article examines why effective stress approaches have failed to describe the mechanics of unsaturated granular media. Profound differences in the fabric of dry and wet materials show the relevance of contact and force networks in the search for a generalized effective stress principle.

A light-pulse-driven transition from a charge-density wave to a Tomonaga-Luttinger liquid is demonstrated, focusing on characteristic effects in the Edwards fermion-boson model.

A novel approach using the interplay between loss and localization to achieve incoherent perfect absorption is proposed. By engineering the losses of a flat-band lattice, a robust incoherent perfect absorption that is immune to disorder and defects is demonstrated.

Raman optical activity provides direct spectroscopic evidence for the existence of a highly unconventional field-induced phase in the proximate Kitaev material $\alpha$-RuCl${}_3$. This phase is characterized by the presence of fully chiral magnetic excitations.

By placing quantum-dot emitters at different positions in the cavity mode of the electric field within a GaAs-Al${}_{0.95}$Ga${}_{0.05}$As micropillar, the effects of noncavity modes on Purcell factor, $\beta$ factor, and collection efficiency are quantified, with results suggesting common experimental practice systematically overestimates the Purcell factor. It is also shown that the zero-phonon line and phonon-assisted emission into the cavity mode HE${}_{11}$ is suppressed by positioning dots at the field node.

Correlation functions up to the fifth order between atoms in a degenerate Fermi gas of metastable helium atoms are measured, with antibunching observed for all orders in a direct demonstration of the Pauli exclusion principle. The results agree well with a simple model based on the decomposition of higher order correlation functions into lower orders via Wick’s theorem.

A train of laser pulses guided by a 100-mm-long, all-optical plasma channel resonantly excites a large amplitude plasma wave. Pulse trains of a similar kind could be generated by joule-scale thin-disk lasers, offering a route to driving GeV-scale plasma accelerators at kilohertz pulse repetition rates.

How an ac driving can tune the diode efficiency of an arbitrary supercurrent diode is shown. Unit efficiency can be achieved in the slow-driving regime.

Nematic solid tori subject to tangential anchoring feature defect structures despite not being topologically required. Their metastability results from the presence of energy barriers accounting for the bulk rearrangement that would be required for the nematic to transition from defect-populated to defect-free states.

Lyapunov spectra of nonlinear unitary-circuit maps are used to unravel the crossover between two thermalization slowing-down universality classes close to integrability, triggered by the strength of incorporated disorder.

An algorithm is presented to program a desired Hamiltonian by connecting a physical system to a quantum computer.

This article studies the nonlocal properties of Majorana states, by looking at the waiting times between consecutive charge transfers across the interferometer and the information encoded in the correlations between these waiting times.

This article explores the possibility of using pulsar timing arrays as proxies for the detection of gravitational waves and, thus, as tools for probing signatures of the early universe.

An acoustic mapping of the Hatano-Nelson model using a transfer matrix approach is proposed. The experimental results, using a nonreciprocal network of actively controlled loudspeakers, show the emergence of the non-Hermitian skin effect and the boundary sensitivity.

A nonlinear dynamical Hall effect unique to layered materials with chiral symmetry, which is driven by the joint action of in-plane and time variation of out-of-plane ac fields, is proposed. It has a band geometric origin in a mixed quantum metric characteristic of interlayer coherent electron wave functions.

Recent experiments revealing magnetic memory in the superconductor 4$Hb$-TaS${}_2$ call for a theoretical explanation of spontaneous vortex creation without spontaneous time-reversal symmetry breaking. This mean-field parton theory offers such an explanation in terms of vortices in the slave boson condensate, thereby introducing the notion of a type-II heavy Fermi liquid.

A conserving and beyond-Gaussian model is developed describing the dynamics of a Bose-Einstein condensate following a quench to unitarity, a paradigmatic example of an out-of-equilibrium strongly interacting quantum system. By integrating to previously inaccessible quench times, it is shown that the postquench dynamics are predominantly driven by the sequential development of coherent few-body correlations.

It is shown that the astrophysical linear buoyancy instability can be tackled as a non-Hermitian topology problem, exhibiting exceptional long-wavelength modes.

APS has selected 156 Outstanding Referees for 2024 who have demonstrated exceptional work in the assessment of manuscripts published in the Physical Review journals. A full list of the Outstanding Referees is available online.

Three journals are excited to announce a new article type, “Perspectives,” to provide forward-looking views of cutting-edge science that has recently emerged or is enjoying renewed activity.