Thermal operations are quantum channels that play a central role in deriving thermodynamic limitations in quantum systems. However, they were originally defined by implementation procedures rather than by fundamental principles. Alternative models of thermal processes have been proposed, but they obscure the resources required for implementation. Here, we identify the universal principle that separates these models. We show that thermal operations are uniquely characterized by a purely quantum information-theoretic property, which we call informational equilibrium. This formulation does not assume a particular Hamiltonian or even a notion of temperature: a channel is a thermal operation precisely when it leaves its environment invariant whenever the system is prepared in equilibrium. In this way, the usual energetic description of equilibrium (i.e., Gibbs states) emerges as a representation of an underlying informational constraint. Extending this framework, we note that enforcing environment invariance for all system inputs leads to catalytic channels, which idealize perfectly reusable heat baths. This informational equilibrium perspective culminates in a hierarchy for doubly-stochastic quantum channels, with strict separations between the classes. Our refined hierarchy sharpens the failure of the Birkhoff–von Neumann theorem in the quantum regime, and highlights the richer structural landscape of quantum channels compared to classical stochastic processes that cannot be captured by state-convertibility relations.

Although entanglement can boost metrological precision beyond the standard quantum limit, the advantage often disappears with particle loss. We demonstrate that scrambling safeguards precision by dispersing information about the encoded parameter into many-body correlations. For Haar-random scrambling unitaries, we derive closed-form analytical expressions for the average quantum Fisher information of the reduced state after tracing out lost particles. The result exhibits a sharp threshold: majority subsystems retain essentially the full quantum Fisher information, while minority subsystems contain negligible information in the large-system limit. We link this threshold to the scrambling-induced transition from area-law to volume-law entanglement and the associated growth of the Schmidt rank. We outline two realizations—a brickwork circuit and chaotic XX-chain evolution—and demonstrate the protection of one-axis-twisted probes for loss of fewer than half the particles.

We investigate the charge-charge correlation (QQC) in electron-positron annihilation as a probe of charge dynamics in quantum chromodynamics. While generally divergent beyond leading order, we show that the QQC is infrared and collinear safe in the back-to-back limit, a property that we dub leading-power safety. This enables an analytic perturbative treatment that bypasses the reliance on nonperturbative track or fragmentation functions. Using soft-collinear effective field theory, we derive a factorization theorem and determine its logarithmic behavior analytically up to four loops in QCD, uncovering remarkable connections with the energy-energy correlation (EEC). Prior to this Letter, the behavior of the QQC beyond leading order was entirely unknown; we now establish its resummation to next-to-next-to-next-to-next-to-leading logarithmic (${\mathrm{N}}^4\mathrm{LL}$) accuracy, placing it among the observables with the highest perturbative precision alongside the EEC. Our results are validated through a numerical analysis using event2, exhibiting excellent agreement with the predicted singular terms. This Letter establishes the QQC as a novel, calculable probe of charge dynamics and unveils a new window into the inner workings of non-Abelian gauge theories.

Recent theoretical studies suggest that solenoidal turbulence can significantly enhance fusion reactivity, yet no standard diagnostic exists to directly measure these solenoidal flows in high-energy-density plasmas, nor to distinguish between solenoidal and compressional turbulence. We propose a method that directly diagnoses the energy and spatial structure of this rotational turbulence using the cross-polarization scattering of a probe laser. By coupling to the plasma vorticity, the scattering generates a cross-polarized signal proportional to the turbulent vorticity, effectively acting as a calorimeter for shear flows. We identify a diffractive scattering signature analogous to “Debye-Scherrer ring” that reveals the eddy size distribution. We show that this technique is applicable to National Ignition Facility (NIF) implosion conditions and other high-energy-density scenarios.

Motivated by the recent twisted ${\mathrm{MoTe}}_2$ experiment [Wang et al., Magnetic Signatures of a Putative Fractional Topological insulator in twisted ${\mathrm{MoTe}}_2$, arXiv:2601.18508], we develop a disordered interacting edge theory of a fractional topological insulator at ${\nu }_{\mathrm{tot}}=4/3$, consisting of two time-reversal-conjugated $\nu =2/3$ fractional quantum Hall states. For an $S_z$-conserving edge, we uncover three distinct phases with two possible conductance values per edge in the long-edge limit: $\frac{2}{3}(e^2/h)$ and $\frac{4}{3}(e^2/h)$. In the presence of $S_z$-changing perturbations (e.g., Rashba spin-orbit coupling), an interaction-induced insulating edge state can emerge without breaking time-reversal or charge-conservation symmetry, corresponding to the absence of a topologically protected edge state. We show an exact mapping (with a special choice of parameters) to a noninteracting fermionic theory exhibiting Anderson localization, and the weak-coupling phase diagrams are also constructed, showing that symmetric localization can emerge regardless of other $S_z$-conserving perturbations. Our results showcase an explicit, experimentally relevant example that the edge-state two-terminal transport can yield false-negative results in identifying the ${\nu }_{\mathrm{tot}}=4/3$ fractional topological insulators.

Magnonic frequency combs, characterized by a series of discrete frequency lines, have emerged as a promising frontier in magnon spintronics, with potential applications in advanced information processing and sensing technologies. Although the three-magnon scattering process is widely recognized as a fundamental mechanism for generating these combs, its experimental realization has remained challenging due to the high threshold power and strict conservation of momentum and energy. Here, we propose a novel mechanism for the stimulated generation of magnonic frequency combs that overcomes these limitations. Our approach offers precise and efficient control over key comb properties, including spacing between spectral lines and the number of lines. Importantly, phase-sensitive heterodyne measurements of the reflected microwave signal reveal stable phase locking between comb lines, providing direct evidence of mutual coherence. We substantiate this mechanism through a robust combination of theoretical modeling, micromagnetic simulations, and experimental validation. This Letter not only demonstrates the feasibility of our method but also opens new pathways for integrating magnonic frequency combs into practical spintronic devices.

Magnons provide a route to ultrafast transport and nondestructive readout of spin-based information transfer. Here, we report magnon transport and its emergent anisotropic nature in ${\mathrm{BiFeO}}_3$ layers confined between ultrathin layers of the antiferromagnet ${\mathrm{LaFeO}}_3$. Because of the confined state, ${\mathrm{BiFeO}}_3$ serves as an efficient magnon transmission channel as well as a magnetoelectric knob by which to control the stack by means of an electric field. We discuss the mechanism of the anisotropic spin transport based on the interaction between the antiferromagnetic order and the electric field. This allows us to manipulate and amplify the spin transport in such a confined geometry. Furthermore, lower crystal symmetry and suppression of the spin cycloid in ultrathin ${\mathrm{BiFeO}}_3$ stabilizes an antiferromagnetic state exhibiting a nontrivial sign inversion of the spin current, which is a characteristic of an altermagnet. This Letter provides an understanding of the anisotropic spin transport in complex antiferromagnetic heterostructures where ferroelectricity and altermagnetism coexist, paving the way for a new route to realize electric-field control of a novel state of magnetism.

We report dynamic energy transport across multicomponent molecular junctions observed at the atomic level. A clear temporal sequence of energy transfer is revealed at early times following photoexcitation of Au(111) bonded with self-assembled monolayers of alkanethiols: from the gold surface layer to the head groups and then to the methylene lattice. Remarkably, the structural dynamics of the gold surface layer differ significantly from those of clean gold. The methylene lattice dynamics exhibit chain-length insensitivity but with a length-dependent retention time to reach full thermalization. Our results show high interfacial thermal conductance and high thermal conductivity for the methylene lattice.

We have investigated the dynamics of nonentangled and weakly entangled polyisoprene (PI) melts using neutron spin echo spectroscopy and pulsed field gradient NMR and compared the spectra with those from a highly entangled PI melt. Except for Brownian diffusion, which was observed in the long-time regime using NMR, the spectra from nonentangled and weakly entangled PI chains were identical. Dividing out Brownian diffusion, these reduced spectra also quantitatively agree with those from the highly entangled PI melt. Reevaluating the results for poly(butylene oxide) leads to an identical observation, indicating universality. These experiments provide quantitative proof of key predictions of theory: (i) the correlation hole potential governs both the subdiffusivity of nonentangled systems and the cooperative dynamics within the entanglement volume, and (ii) as the spectra from a weakly entangled PI melt also coincide with those from the shorter and highly entangled PI, the entanglement potential, which creates topological constraints, acts in the same way for weakly and strongly entangled melts.

We introduce accelerated sequential posterior inference via reuse (ASPIRE), a broadly applicable framework that transforms existing posterior samples and Bayesian evidence estimates into unbiased results under alternative models without rerunning the original analysis. ASPIRE combines normalizing flows with a generalized sequential Monte Carlo (SMC) scheme, enabling efficient updates of existing results and reducing total likelihood evaluations and wall times by factors of up to 5.8 and 5.5, respectively, with larger gains per posterior sample. This addresses a growing problem in gravitational-wave astronomy, where events must be repeatedly reanalyzed under different models or physical hypotheses. We show that ASPIRE reproduces full Bayesian results when switching waveform models or adding physical effects such as spin precession and orbital eccentricity. With this statistical robustness, ASPIRE turns repeated reanalyses into fast, reliable updates—paving the way for systematic studies of waveform systematics, scalable reanalyses across large event catalogs, and broadly applicable Bayesian reanalysis across other scientific domains.

We report a follow-up axion haloscope search near 1.036 GHz that completes and extends our previous work [Ahn et al. Phys. Rev. X 14, 031023 (2024)], in which a portion of the HEMT-based data could not be analyzed due to unrecorded experimental information. While recovering this dataset, we identified an excess near 1.036 GHz that satisfied our candidate-selection criteria, motivating dedicated validation studies, including independent cross-checks and reexamination with the original apparatus. The excess did not persist under these investigations and was not confirmed as an axion dark-matter signal. We subsequently extended the search over a 20-MHz band surrounding the candidate using a quantum-noise-limited amplifier, achieving sensitivity close to the Dine-Fischler-Srednicki-Zhitnitsky benchmark. In the absence of a confirmed signal, we set improved 90% confidence-level upper limits on the axion-photon coupling over the frequency range 1.026–1.045 GHz. This Letter highlights the importance of robust candidate-validation strategies as haloscope searches approach discovery-level sensitivity.

Angular momentum conservation stands as one of the most fundamental and robust laws of physics. In discrete lattices, however, its realization can deviate markedly from the continuous case, especially in the presence of nontrivial momentum-space band touchings. Here, we investigate angular momentum conservation associated with quadratic band-touching points (QBTPs) in two-dimensional lattices. We show that, unlike in graphene lattices hosting linear band-touching points, the conventional angular momentum is no longer conserved near QBTPs. Instead, we identify a generalized total angular momentum that remains conserved for both linear band-touching points and QBTPs, inherently determined by the topological winding number at the band-touching point. Using a photonic Kagome lattice, we experimentally demonstrate the conservation of generalized total angular momentum through pseudospin-orbital angular momentum conversion. Furthermore, we show that this conservation principle extends to a broad class of discrete lattices with arbitrary pseudospin textures and higher-order winding numbers. These results reveal a fundamental link between pseudospin, angular momentum, and topology, establishing a unified framework for angular momentum dynamics in discrete systems.

Three-dimensional spiral injection enables beam storage in ultracompact rings with nanosecond revolution periods. We report first storage of a $297\mathrm{keV}/c$ electron beam in a 22 cm weak-focusing ring with a 4.7 ns revolution period using a 140 ns kicker pulse. A scintillating-fiber detector observes signals $>5\sigma$ above noise for $\ge 1\mathrm{\mu }\mathrm{s}$, and varying the weak-focusing field potential shifts the stored-beam region, consistent with Monte Carlo predictions, validating beam storage. This proof-of-principle opens a path to ultracompact storage rings for next-generation precision measurements including short-lived particles.

The interactions of anyonic quasiparticles (vortices) in a Chern-Simons-Landau-Ginzburg theory of the fractional quantum Hall effect is investigated and we show that it manifestly realizes a hybridization of type I or II superconductivity. Through Gauss’s law, each vortex simultaneously carries a flux quantum and a proportional Noether charge, thereby realizing an anyonic excitation. The Chern-Simons coupling modifies the screening structure of the gauge fields, producing complex-conjugate masses that yield a common magnetic and electric penetration depth with an oscillatory phase. This altered asymptotic behavior breaks the conventional type-I and type-II dichotomy of the Ginzburg-Landau model, thereby enhancing the superconducting typology within a single-component condensate. As a result, vortex anyons experience short-range repulsion and long-range attraction, enabling the formation of separated multivortex bound states with nonmonotonic interaction energy. This provides a minimal topological route to hybrid superconductivity without multicomponent order parameters or nonlocal interactions.

Chemical short-range order (SRO) is an intrinsic feature of the atomic structures in multiprincipal element alloys (MPEAs). Effective control of SRO structures could considerably improve the strength and ductility of MPEAs. However, the experimental characterization of SRO remains highly challenging due to their extremely high complexity and small sizes. This Letter presents that, by integrating experiments and atomistic modeling, positron annihilation spectroscopy could directly identify SRO structures in bcc NbTiZr MPEA. It was revealed that both Zr-rich and Nb-rich regions are formed in the SRO structure. The effects of lattice relaxation and electron charges lead to an increased positron annihilation contribution from Zr and a corresponding decrease from Nb. This subtle change was directly captured by integrating theoretical and experimental positron annihilation Doppler broadening spectra. The evolution of SRO was further validated by synchrotron small angle x-ray scattering. Unlike conventional localized techniques, the proposed approach provides a nondestructive, statistically averaged and element-sensitive probe, establishing a unique route to identify local chemical fluctuations in complex materials.

Polar surfaces, known for their unique electronic and chemical properties, play vital roles in catalysis and electronics, yet their atomic structures remain difficult to resolve due to intrinsic instability often mitigated by surface reconstruction. However, the role of entropy, particularly vibrational entropy, in stabilizing such reconstructions is not well understood. Herein, we combine in situ atomic-resolution spherical aberration-corrected scanning transmission electron microscopy, density-functional theory calculations, and a differential evolution algorithm for global structural search to resolve the ($1\times 1$) reconstructed structure of the classical polar rutile ${\mathrm{TiO}}_2(111)$ surface. Crucially, we demonstrate that this reconstruction is predominantly stabilized by vibrational entropy at high temperatures. These findings not only highlight the importance of vibrational entropy in surface reconstructions but also advance our understanding of compensation mechanisms on polar surfaces by highlighting entropy as a critical stabilizing factor.