We present a new mechanism for long-range entanglement (LRE) in strongly symmetric many-body mixed states that does not rely on symmetry anomalies or long-range correlations. Our primary example is the maximally mixed state in the translation-invariant subspace on a one-dimensional ring. This state is LRE because translationally symmetric short-range entangled states span a subspace whose dimension grows only polynomially with system size, whereas the full translation-invariant subspace grows exponentially. We further discuss certain unconventional properties of this state, including logarithmically growing conditional mutual information, strong-to-weak spontaneous symmetry-breaking, and Rényi-index-dependent operator-space entanglement. We also construct a geometrically non-local Lindbladian to stabilize this state as the steady state. Our results identify dimensional mismatch as a novel route to LRE that is intrinsic to many-body mixed states.

We investigate realizations of (1+1)-dimensional fusion category symmetries on tensor-product Hilbert spaces, allowing for mixing with quantum cellular automata (QCAs). It was argued recently that any such realizable symmetry must be weakly integral. We develop a systematic analysis of QCA-refined realizations of fusion categories and prove two statements. First, we show that, under certain physical assumptions on defects, any QCA-refined realization has QCA and symmetry-operator indices determined by the categorical data, up to the freedom of redefining the symmetry operators. Second, we construct a lattice model that provides a QCA-refined realization for any weakly integral fusion category symmetry on a tensor product Hilbert space. We also compute indices of the QCAs in our lattice model and show agreement with the first result. As an application of the general construction, we give an explicit QCA-refined realization of general Tambara-Yamagami categorical symmetries.

Evaporating colloidal droplets have long been used as model systems to understand capillarity, interfacial transport, and particle assembly, most prominently through the coffee ring effect. In classical descriptions, suspended particles are treated as passive tracers carried by evaporation-driven capillary flow, with additional influence from Marangoni stresses, wettability, and contact line pinning. More recent studies, however, show that this picture changes significantly when the particles themselves are active. Systems containing motile microorganisms, chemically active colloids, or externally driven particles can continuously inject energy or generate gradients within the droplet, leading to self-driven flows, modified interfacial stresses, and dynamic contact line behavior. In this Perspective, we bring together these developments, identify the key mechanisms governing active droplets, highlight the role of bubble-mediated flows, and outline strategies for controlled deposition and functional interface design.

The gravitational path integral produces an asymptotic expansion in $G_N$, a fact which is puzzling in the case of observables that are expected to fluctuate wildly. Wormholes appear to compute ensemble averages of functions of such observables, though in typical constructions of AdS/CFT, there are no parameters to average over except, in some examples, a single integer $N$. We introduce a procedure that we call ``Mellin averaging'' to define a sort of asymptotic average of a function of $N$. We argue that Mellin averaging over $N$ may suffice to reproduce the apparent randomness seen in wormhole physics, provided that the dual theory admits an analytic continuation in $N$ and the relevant observables fluctuate on superpolynomially small scales in $N$. As a test case, we consider the spectral form factor in the regime where the double cone is believed to dominate the gravitational path integral and compare to a random matrix theory in which $N$ behaves as a continuous variable. We also describe some toy models of analytic continuation in $N$: a qubit model that can be analytically continued in $N$, and an explicit construction of a deterministic function of $N$ that simulates a sequence of independent draws from a Gaussian ensemble.

Scaling Scientific Machine Learning (SciML) toward universal foundation models is bottlenecked by negative transfer: the simultaneous co-training of disparate partial differential equation (PDE) regimes can induce gradient conflict, unstable optimization, and plasticity loss in dense neural operators. In particular, broadband open-channel fluid dynamics and boundary-dominated porous media flows impose incompatible spectral and geometric demands on a single dense parameter path. We introduce Shodh-MoE, a sparse-activated latent transformer architecture for multi-physics transport. Shodh-MoE operates on compressed 16^3 physical latents produced by a physics-informed autoencoder with an intra-tokenizer Helmholtz-style velocity parameterization, restricting decoded states to divergence-free velocity manifolds. The model guarantees exact mass conservation, achieving a physically verifiable velocity divergence of ~2.8 x 10^-10 (evaluated post-hoc in FP64) on 128^3 grids. A Top-1 soft-semantic router dynamically assigns localized latent patches to expert subnetworks, enabling specialized parameter paths for distinct physical mechanisms while preserving shared experts for universal symmetries. In a 20,000-step distributed pretraining run over mixed three-dimensional physical tensors, routing telemetry shows autonomous domain bifurcation: held-out validation tokens from the open-channel domain route exclusively to Expert 0, while porous-media tokens route exclusively to Expert 1. The model converges simultaneously across both regimes, achieving latent validation MSEs of 2.46 x 10^-5 and 9.76 x 10^-6, and decoded physical MSEs of 2.48 x 10^-6 and 1.76 x 10^-6. These results support sparse expert routing as a practical architectural mechanism for mitigating multi-physics interference in universal neural operators.

High-temperature dimensional reduction provides a systematic effective field theory framework for studying finite-temperature thermodynamics and cosmological phase transitions. While the matching of super-renormalizable operators in the resulting three-dimensional effective theories is well established, the matching of higher-dimensional operators has recently been reinvigorated. These operators become phenomenologically relevant in strong first-order phase transitions where they quantify the convergence of the high-temperature expansion. This work automates the matching of generic three-dimensional dimension-five and -six operators for arbitrary models containing scalars, fermions, and gauge fields, implemented as an extension of the Mathematica package DRalgo. We present the operator basis, the matching procedure, and explicit examples including a scalar-Yukawa model, hot QCD, and the full Standard Model up to dimension six, covering operators mixing the strong and electroweak sectors as well as parity-violating contributions. Redundant operators, gauge dependence, and the corresponding field redefinitions are discussed in detail. The code and example model files are publicly available at https://github.com/DR-algo/DRalgo.

The potential to detect axion dark matter through astrophysical processes has shown high promise in recent years. We therefore expand on previous work studying the axion-to-photon conversion efficacy of neutron stars and the interstellar medium (ISM) in this endeavor, respectively. For neutron stars (NS), we examine the possibility of a background signal emanating from all NS magnetospheres in the galaxy. Using a heuristic Galactic model, we find a significant background signal emanating from such magnetospheres in the Milky Way. This signal, while weak in absolute power ($\gtrsim 1$ mJy sr$^{-1}$ from the Galactic Center, at 2 GHz), can be detected through new statistical techniques with current instrumentation like the Atacama Large Millimeter Array (ALMA) at high radio frequencies (200 - 950 GHz). These techniques make use of higher order statistics like spectrally-limited ($\sim 300$ km s$^{-1}$) increases in confusion noise levels and kurtoses of survey images, and also show promise for general population estimation techniques. For the ISM, we consider Primakoff processes between free electrons and axions, and derive typical signal strengths of $10^{-15}$ Jy sr$^{-1}$ $\cdot$ $m_a$/eV, with a local, cosmological upper bound of $10^{-8}$ Jy sr$^{-1}$ $\cdot$ $m_a$/eV. Hence, we find that any diffuse axion signal from the ISM and other, large-scale, astrophysical plasmas to be too weak to be detected with modern technologies. We therefore find that the best avenue towards detecting a potential quantum chromodynamics (QCD) axion dark-matter particle is through the radio imaging of large swaths of the Galactic Center and other regions where we expect large numbers of pulsars and neutron stars.

The performance of quantum resource manipulation protocols, including key examples such as distillation of quantum entanglement, is measured in terms of the rate at which desired target states can be produced from a given noisy state. However, to achieve optimal rates, known protocols require precise tailoring to the quantum state in question, demanding a perfect knowledge of the input and allowing no errors in its preparation. Here we show that distillation of quantum resources in the framework of resource non-generating operations can be performed universally: optimal rates of distillation can be achieved with no knowledge of the input state whatsoever, certifying the robustness of quantum resource distillation. The findings apply in particular to the purification of quantum entanglement under non-entangling maps, where the optimal rates are governed by the regularised relative entropy of entanglement. Our result relies on an extension of the generalised quantum Stein's lemma in quantum hypothesis testing to a composite setting where the null hypothesis is no longer a fixed quantum state, but is rather composed of i.i.d. copies of an unknown state. The solution of this asymptotic problem is made possible through new developments in one-shot quantum information and a refinement of the blurring technique from [Lami, arXiv:2408.06410].

This chapter tells the still-unfolding story of extracting polarization signatures from general relativistic magnetohydrodynamics simulations of accretion disks. In some sense, this effort is premature as there are still very few results of this kind. Much more abundant are phenomenological models. Nevertheless, we feel now is the time to rally the community to this cause. Since the focus of this book is on X-ray polarimetry, we focus exclusively on simulations of accretion onto compact objects. Most of the relevant work so far has been on black hole accretion disks, though neutron stars are also viable targets for X-ray polarimetry. The focus of our chapter is on how X-ray polarimetry coupled with accretion simulations might help us better understand properties of the disks, coronae, and jets that are the dominant components of accreting compact sources. We briefly illustrate the promise of this technique by demonstrating how it has already been used in the case of the Event Horizon Telescope (using radio polarimetry). We also speculate about where this field may be heading in the near future.

We formulate axion magnetohydrodynamics beyond the ideal limit, retaining axion inertia and the essential physics of non-ideal plasmas from first principles. In this framework, regions where magnetic flux freezing breaks down acquire a new physical role: whenever $\mathbf{E} \cdot\ \mathbf{B} \neq 0$, magnetic dissipation acts as a localized source of axion radiation. We show that magnetic reconnection naturally excites mixed Alfvén-axion modes, enabling coherent energy exchange between magnetic fields and axions in magnetically dominated environments. In neutron stars and magnetars, this mechanism leads generically to transient axion bursts powered by reconnection--driven Alfvénic dissipation. We connect this production process to observational prospects and derive a characteristic sensitivity to the axion--photon coupling, complementary to searches based on static magnetic fields.

Using the post-Newtonian effective field theory (PN-EFT) formalism for spinning gravitating bodies, we derive the next-to-leading-order (NLO) spin-orbit potential and Hamiltonian for a system of N spinning bodies in general relativity. This extends the EFT treatment of the binary case to arbitrary N. We present two derivations: one in the generalized canonical gauge, and one based on the covariant spin supplementary condition (SSC), followed by a noncanonical transformation to canonical variables. In both approaches, the only new contributions beyond the binary case are three-body interaction diagrams. The canonical Hamiltonians obtained from the two EFT routes agree with the known ADM N-body Hamiltonian of Hartung and Steinhoff up to a canonical transformation.

In epithelia, how do collective cell migration and tissue spatial organization feedback on each other? We address this question through large-scale numerical simulations of the cellular Potts model. By accounting for both cell morphology and cytoskeletal activity, we uncover a remarkably rich phase diagram featuring multiple types of orientational order, either as distinct phases or coexisting across length scales. We identify a specific pathway in parameter space along which a gradual increase in the actin polymerization rate drives a phase transition into a long-range flocking state. Simultaneously, quasi-long-range nematic order emerges at length scales much larger than the cell size due to the combined effects of directed motion and lateral cell-cell interactions. At length scales comparible to cell size, however, cells adopt an approximatively hexagonal morphology, resulting in hexanematic order, similar to that observed in reconstituted Madin-Darby Canine Kidney (MDCK) cell monolayers. With further increases in actin polymerization, nematic order becomes fully long-range, while hexatic order remains quasi-long-range and confined to short length scales, but independent of cytoskeletal activity. When noise is sufficiently low to allow crystallization at finite actin polymerization rate, cycling the cell-monolayer across the melting transition yields an example of phenotypical hysteresis, reminiscent of that observed across the epithelial-mesenchymal transition.

Pattern formation in soft, active, and biological matter is described by two ostensibly distinct continuum frameworks: phase-field theories driven by chemical-potential gradients, and mass-conserving reaction-diffusion (McRD) dynamics governed by local interconversion kinetics. Here we establish a constructive, equation-level duality valid in the nonlinear, far-from-equilibrium regime. McRD is the broader class: every chemical-potential theory with conserved order parameters embeds as the slow dynamics on an attracting manifold of an McRD system; conversely, every McRD with attractive nullcline admits an exact chemical-potential representation in the fast-interconversion limit, with the constitutive relation set by the nullcline. The construction resolves the generic non-invertibility of the chemical-potential as a function of density in phase-separating regimes by embedding it as an attracting manifold in an extended two-field description with conserved total density. Gradient stiffness maps faithfully onto an intrinsic reaction-diffusion length set by the auxiliary field, yielding a diagonal-diffusion normal form whose interface profile matches the original Cahn-Hilliard model by construction. The duality yields an explicit dictionary for phase coexistence: the Maxwell equal-area construction is exactly equivalent to the reactive turnover-balance condition. It extends to weakly nonconservative dynamics, unifying reaction-arrested coarsening and mesa splitting, and to multicomponent theories with broken Maxwell symmetry. As a concrete payoff, the dual sharp-interface picture yields a closed-form velocity law for traveling waves in nonreciprocal Cahn-Hilliard dynamics, in quantitative agreement with simulations.

We show that the low-energy states of non-Abelian topological orders possess extensive magic which is long-ranged, and cannot be eliminated by a constant-depth local unitary circuit. This refines conventional notions of complexity beyond the linear circuit depth which is required to prepare any topological phase, and provides a new resource-theoretic characterization of topological orders. A central technical result is a no-go theorem establishing that stabilizer states--even up to constant-depth local unitarie--cannot approximate low-energy states of non-Abelian string-net models which satisfy the entanglement bootstrap axioms. Moreover, we show that stabilizer-realizable Abelian string-net phases have mutual braiding phases quantized by the on-site qudit dimension, and that any violation of this condition necessarily implies extensive long-range magic. Extending to higher spatial dimensions, we argue that any state obeying an entanglement area law and hosting excitations with nontrivial fusion spaces must exhibit extensive long-range magic. This applies, in particular, to ground-states and low-energy states of higher-dimensional quantum double models.

Conservation laws of a class of time-dependent damped nonlinear multidimensional wave equations are derived by Noether's theorem. For arbitrary nonzero damping coefficient and nonlinear interaction term, its infinitesimal variational symmetries span a Euclidean algebra $\euclid(n)$ of space translations and rotations. They produce conservation of linear and angular momentums. For some specific forms of these two terms symmetry algebra is enlarged to a subalgebra of the conformal algebra $\conf(1,n)$ and in this case more interesting conservation laws are found.

Neutrino oscillation experiments present anomalous results across a vast range of baselines and energies. Here we show that a 3+1 scenario in which sterile neutrinos feel a novel matter potential $V_s$ proportional to background density of ordinary or (asymmetric) dark matter is able to explain several anomalies. At low-energies ($E\lesssim$ 1 TeV) the model behaves as an effective 3-flavor NSI-like scheme among active flavors and eliminates the tension between the two LBL experiments NOvA and T2K provided that the potential is negative and the two sterile mixing angles $θ_{14}$ and $θ_{24}$ are non-zero. A further indication in favor of a negative non-zero potential comes from the anomalous excess of $ν_e$-like events observed in Super-Kamiokande atmospheric neutrinos, which, in the new scenario is explained by a modification of the 3-flavor resonance at few GeV. A high energies ($E\gtrsim $ 1 TeV) the new framework reveals its 4-flavor nature and produces a resonant behavior at $E \simeq$ 10 TeV as hinted at by IceCube. We identify an irreducible 3-level dynamics generating a new resonance in the $(ν_e, ν_μ)$ sector intertwined with two conventional resonances in the $(ν_e, ν_s$) and $(ν_μ, ν_s)$ systems. The novel amplification mechanism manifests with the emergence of effective mixing angles in matter ($θ_{12}^m$ or $θ_{13}^m$) involving active neutrinos. The scenario requires values of $f = V_s/|V_{NC}| \sim -20 $, $Δm^2_{41} \sim 60 $ eV$^2$, $|U_{e4}|^2\simeq \sin^2θ_{14} \simeq 0.01-0.03$ and $|U_{\mu4}|^2 \simeq \sin^2θ_{24}\simeq 10^{-4}-10^{-3}$. Such a very small size of $|U_{\mu4}|^2$ eliminates the tension between IceCube and the other $ν_μ$ disappearance searches. The model can be directly probed by KATRIN, which is very sensitive to the electron-sterile neutrino admixture in the region of high $Δm^2_{41}$.

It is of a general interest to look for signatures of stellar bodies orbiting supermassive black holes (SMBHs) in galactic nuclei other than the Galactic center. Previously stellar transits were analyzed in UV, optical, and X-ray domains as well as potential microlensing signatures due to more compact bodies orbiting SMBH accretion disks. Here we complement previous studies by considering nearby ($z=0.001$) radio-loud active galactic nuclei targeted by different facilities in the millimeter domain. At these wavelengths the radio core is sufficiently small so that it can be occulted by large evolved stars in dense nuclear star clusters. We find that in the millimeter domain evolved stars with stellar radii of $\gtrsim 500\,R_{\odot}$ can cause eclipses with the relative depth of $\sim 10\%$. Typical recurrence timescales are at least 10 years and the eclipse durations are $\sim 10$ days. Towards lower frequencies the eclipse temporal profiles become shallower and broader while towards higher frequencies they are deeper and narrower. Although expected to be rare due to selection effects and evolved stars being prone to tidal disruption, recurrent eclipses of mm radio cores can be applied to infer SMBH masses and constrain the composition of the Nuclear Star Cluster of the host nucleus.

Ultrafast diffraction is the cutting-edge technique to extract the atomic temperature at femtosecond timescales, and further related quantities - in particular, electron-phonon coupling strength at elevated electronic temperatures. The present work demonstrates limitations of such an analysis, emphasizing the importance of careful evaluation of the evolution of the Debye temperature. It is shown that, due to the sensitivity of the Debye-Waller analysis to this parameter, neglecting its changes under electronic excitation may lead to significant deviations of the atomic temperature extracted from its true values.

A silicon microring resonator with an anisotropic beryllium sulfide (BeS) cladding is proposed for polarization-selective detection of exhaled-breath volatile organic compound biomarkers. The anisotropic dielectric response of BeS enables the transverse-electric (TE) and transverse-magnetic (TM) modes to probe orthogonal components of the cladding permittivity tensor, generating two independent optical observables from a single device. Five clinically relevant biomarkers are investigated: acetone, isoprene, 4-hydroxyhexenal, 2-propenal, and benzene. First-principles optical constants are incorporated into three-dimensional finite-difference time-domain simulations to evaluate the sensing response. The TE mode exhibits a uniform resonance shift of 0.263 nm across all analytes and serves as a concentration reference channel, while the TM mode produces analyte-specific shifts ranging from 0.200 to 0.426 nm. A unique TM amplitude inversion is observed for benzene, enabling additional discrimination. The resulting dual-polarization response forms a two-dimensional optical fingerprint that distinguishes all five biomarkers without requiring a sensor array or multiple functionalized resonators. The device achieves quality factors of 4520 and 3151 for the TE and TM modes, respectively, with sensitivities up to 6.5 nm/RIU, figures of merit up to 14.9 RIU^-1, and detection limits as low as 1.5 mRIU. Cross-sensitivity analysis further shows that CO2 and H2O produce negative TM resonance shifts, separating interferents from target biomarkers in the fingerprint plane. The proposed platform demonstrates a compact route toward array-free photonic breath analysis using intrinsic cladding anisotropy.

We report the discovery of a new candidate pulsating ultraluminous X-ray source (PULX) in NGC 5128 (Centaurus A). The candidate, 4XMM J132542.2-425943, is a transient source, identifiable as a clear X-ray point source for $\sim 8$ months in 2014, during its only major recorded outburst. The source flux exceeded $10^{-12}$ erg cm$^{-2}$ s$^{-1}$ at the peak of the outburst. The long-term light curve of 4XMM J132542.2-425943 shows two further, less luminous detections in 2017 and 2024, but was otherwise in quiescence. This behaviour is similar to the class of pulsating transients with outbursts that reach the ultraluminous regime, which includes the well-studied Galactic PULX, Swift J0243.6+6124. However, 4XMM J132542.2-425943 displays a soft X-ray spectrum, making this source distinct from the existing population of PULXs, which typically show hard spectra below $10$ keV. We searched the 2014 XMM-Newton observations for X-ray pulsations, revealing coherent, sinusoidal X-ray pulsations at a frequency of $1.27$ Hz in one XMM-Newton observation (ObsID 0724060801), at a marginal significance. For this signal we measure a pulsed fraction, PF$\approx~15 - 17~\%$ and $\dot{f}~\sim~4~\times~10^{-9}$ Hz s$^{-1}$. However, we find that the intrinsic randomisation employed by XMM-Newton's Science Analysis Software, XMM-SAS, during the data reduction procedure introduces considerable uncertainty in the strength of our marginal pulsations, which varies significantly between consecutive data reduction iterations. We explore the impact of this randomisation and demonstrate that it can generate widespread false positives and false negatives, which, in the context of PULX searches, may cause viable candidates to be unnecessarily discarded or vice versa.

Efficient and selective excitation of lattice vibrations is central to controlling energy flow at the nanoscale, yet remains challenging under conventional optical excitation. Here, we introduce a mid-infrared-assisted phonon amplification approach, termed MIRAPA, that enables efficient energy injection directly into vibrational bonds. Using surface-enhanced resonant Raman scattering in few-layer $\mathrm{MoS_2}$, we exploit strong exciton--phonon coupling to monitor phonon populations. When mid-infrared (MIR) light is introduced, it couples directly to out-of-plane lattice vibrations, leading to room-temperature phonon amplification exceeding $80\%$. Crucially, MIRAPA bypasses electronic excitation pathways, allowing the MIR power density to be nearly $300\times$ lower than that required for visible excitation to achieve comparable enhancement. The resulting phonon modulation is robust, persisting over more than $2800$ on/off cycles and exceeding $15$ hours of continuous-wave laser illumination without degradation. Quantitative analysis yields an effective noise-equivalent power of approximately $0.3\,\mathrm{nW}/\sqrt{\mathrm{Hz}}$ for MIR detection, highlighting the sensitivity of the approach. By combining vibrational selectivity, low-power operation, and long-term stability, MIRAPA provides a robust platform for probing and amplifying phonons in two-dimensional semiconductors. These results open new opportunities for nanoscale vibrational sensing, mid-infrared detection, and phonon-based coherent devices, including routes toward phonon lasing.

The possibility of laser cooling and the presence of closely spaced rovibrational doublets make polyatomic molecules an attractive platform for the $\mathcal{P}$, $\mathcal{T}$-violation searches. We study the spectrum of the lowest rovibrational state of the AcOCH$_3+$ symmetric top molecule. The electronic structure full-electron computation was performed within a relativistic coupled cluster method with double and perturbative triple excitations. The rovibrational wavefunctions are obtained using a coupled channel technique, taking into account all rovibrational effects and anharmonicities of the potential. As a result, the vibrational frequencies, as well as the values of the electric dipole moments for the rovibrational states, were computed.

Independent and identically distributed (i.i.d.) states are ubiquitous in quantum information theory. However, in a practical setting, the i.i.d. assumption is too stringent, and possibly not realistic. A physically more compelling class of 'almost i.i.d.' sources was recently proposed by [Mazzola/Sutter/Renner, arXiv:2603.15792]. In this paper, we introduce two alternative definitions of almost i.i.d. states, based on the normalised quantum Wasserstein distance and on the idea of looking at the average $k$-body marginal. We explore some basic properties of these notions and prove a strict hierarchical relation among them, with Mazzola et al.'s notion being the strictest, the one based on $k$-body marginals the loosest, and the one based on the quantum Wasserstein distance in between. Strict separation is established by means of explicit examples.

Solar pores possess irregular and evolving boundaries that are often far from the ideal circular flux tubes assumed in many magnetohydrodynamic (MHD) oscillation models. To tackle this irregularity in a consistent way for wave analysis, we introduce a framework that employs the convex hull of the pore boundary - derived from intensity minimum error thresholding - as the domain to perform further analysis. Using the modal assurance criterion, we find the range of pore shapes for which this approximation is valid. We demonstrate the usefulness of this framework by applying it to multi-height, high-cadence observations (4170 angstrom continuum, G-band, Na~\textsc{i}, and Ca~\textsc{ii}~K) of a solar pore, and apply Proper Orthogonal Decomposition of the convex hull to determine wave modes. The fundamental sausage ($m=1$) and kink ($m=2$) mode is found to remain reliable, while higher-order fluting modes ($m\ge3$) are strongly degraded by small-scale boundary irregularity. As expected, sausage-like modes dominate the variance at all heights and exhibit a systematic upward shift in frequency, consistent with freely propagating compressive waves. In contrast, the kink-like motions appear weak, confined to a persistent low-frequency peak, and most plausibly interpreted as a forced response to granular buffeting rather than a propagating mode. Together, these results establish a practical methodology for boundary-mode analysis in real, highly structured pores and provide new constraints on the nature and height evolution of MHD waves in the lower solar atmosphere.

We consider the displacement contribution to photoresistance in overlapping Landau levels at radiation frequencies much smaller than the cyclotron frequency. We show that in the limit of short-range disorder and high radiation power, this contribution leads to a new class of magneto-resistance oscillations. These oscillations, which we call radiowave-induced resistance oscillations (RIROs), are distinct from the well known microwave-induced resistance oscillations in the following aspects: (i) their amplitude is independent of power, (ii) their period is controlled by the radiation electric field, rather than by the radiation frequency, and (iii) they can be either $1/B$ or $1/B^2$-periodic, depending on $B$, with the crossover point linked to the width of the cyclotron resonance absorption curve. We also show that RIROs should be readily observed in experiments.

Characterizing large quantum systems with minimal assumptions is a central challenge in quantum information science. Self-testing provides the strongest form of certification by identifying the underlying quantum state solely from observed measurement statistics. However, existing self-testing methods for generic $n$-partite states face a scalability barrier, requiring exponentially many samples in the system size. In this work, we overcome this barrier by introducing a protocol that robustly self-tests almost all $n$-qubit states with only polynomial sample complexity. The key ingredient is an efficient scheme for device-independently evaluating multipartite Pauli measurements, which can be implemented using only a linear number of ancillary Bell pairs together with standard projective and Bell measurements, well within the reach of current quantum technology. Beyond self-testing states, our scheme provides a general framework for implementing a wide range of learning and certification protocols in the device-independent setting, thereby opening a scalable route to device-independent quantum information processing in large-scale quantum networks.

Classifying interactions is key in the physical sciences, and bonding mechanisms in matter-antimatter systems remain particularly enigmatic. Here we focus on a paradigmatic example of positronium hydride (PsH) dimer composed of two protons, two positrons, and four electrons, whose bonding nature has been previously described as either ionic, covalent, or van der Waals-like. Accurate quantum Monte Carlo calculations show that the two positrons occupy a delocalized molecular orbital that envelopes the two hydrogen anions and responds as a collective dipole to an applied electric field. This positronic bonding stems from quantum correlations that resemble a single covalent bond formed between negatively charged pseudo-nuclei, but with a bond strength commensurate with the traditional van der Waals interaction. Our findings suggest that the ability to form delocalized proto-bonds is a more general property of quantum systems, and could be present in a broader class of particles, antiparticles, and quasi-particles interacting with matter.

The classical simulation of quantum algorithms is a crucial tool for circuit development, testing, and validation. Although acceleration using GPUs significantly reduces simulation time, most high-performance simulators rely on vendor-specific frameworks that target data-center hardware. To broaden access to quantum simulation, this work proposes a vendor-agnostic approach targeting the integrated GPUs commonly found in consumer-grade laptops. A primary challenge in state-vector simulation is its inherently poor spatial locality, which creates a memory bandwidth bottleneck. Consequently, baseline implementations experience a severe degradation in relative GPU speedup as the number of simulated qubits increases. To address this limitation, we introduce a state partitioning optimization that reorganizes the quantum state vector to maximize the last-level cache locality and minimize costly main memory fetches. We evaluate this strategy using a Quantum Phase Estimation algorithm across diverse architectures from Intel, AMD, and Apple. The experimental results demonstrate that the proposed optimization successfully mitigates performance degradation at larger qubit scales. In particular, for a 28-qubit simulation, the optimization reversed a performance deficit on an Intel Core i5, improving the GPU speedup over the CPU from 0.95x to 1.89x, and increased the Apple M1 Pro speedup from 3.71x to 5.88x. Overall, this approach yields consistent execution time improvements, demonstrating the viability of integrated GPUs for efficient quantum circuit simulation.

How much energy does a quantum computer consume? Are they more efficient than their classical counterparts? In this work, we make a step towards answering these questions. We define the energy efficiency of a quantum computer as the ratio of the number of algorithms it can perform during a given time over the energy consumed by the hardware during this time. We analyze the most representative physical platforms currently envisioned to be used as building blocks of quantum computers: superconducting qubits, silicon spin qubits, trapped ions, neutral atoms and photonic qubits. Including insights from experts in all these technologies and taking into account algorithm compilation constraints, we discuss the advantages and inconveniences of each platform from an energy standpoint. Beyond providing concrete values of the energy consumption of current quantum computers, we lay the foundation of a framework to benchmark the energy efficiency of any future quantum computing architecture.

Nondestructive detection of single-electron motion is crucial for quantum information processing with electrons trapped in Paul traps. The standard approach in Penning traps is to detect the image current induced on the trap electrodes by the electron's oscillatory motion. However, applying this approach in Paul traps for single electrons is currently hindered by motional frequency fluctuations arising from trap anharmonicities and instabilities in the rf trapping field. In this work, we propose a robust detection scheme exploiting the transient dynamics of parametric driving to overcome these limitations. Distinct from traditional steady-state approaches, our method focuses on the transient regime to break the temporal constraints imposed by steady-state assumptions, thereby enabling fast readout. We show that a controlled ramp of the parametric drive effectively locks the frequency of the electron motion in the transient regime, rendering the signal highly resilient to realistic experimental noise and inherent micromotion. This work paves the way for the experimental realization of nondestructive detection of single-electron motion in Paul traps.