The Quantum Journal

arXiv:2604.11814v1 Announce Type: new Abstract: Quantum mechanics owes much of its extraordinary success to a Hilbertian program of mathematical formalization. Yet, the formalism remains poorly aligned with the practical limitations of computations in finite dimensions and under finite accuracy. In

arXiv:2604.11817v1 Announce Type: new Abstract: Hybrid quantum-classical models offer a promising route for learning from complex data; however, their application to multi-band remote sensing imagery often relies on generic, data-agnostic quantum circuits that fail to account for channel-specific s

arXiv:2604.11823v1 Announce Type: new Abstract: According to various no-go results in the foundations of quantum mechanics, for any system associated to a Hilbert space of dimension higher than two, it is not possible to assign definite truth values to all propositions pertaining to the system with

arXiv:2604.11825v1 Announce Type: new Abstract: Many nonlinear PDEs have singular or oscillatory solutions or may exhibit physical instabilities or uncertainties. This requires a suitable concept of physically relevant generalized solutions. Dissipative measure-valued solutions have been an effecti

arXiv:2604.11830v1 Announce Type: new Abstract: Some skeptical arguments on the physical reality of quantum states are given. First, I argue that the algebraic formalism of quantum field theory in curved spacetime (algebraic QFTCS, AQFTCS) leads to such a skepticism. Of course we have the purely ma

arXiv:2604.11831v1 Announce Type: new Abstract: In hybrid classical-quantum computing, variational quantum algorithms (VQAs) have emerged as a promising approach in the Noisy Intermediate-Scale Quantum (NISQ) era; however, their performance is often hindered by barren plateaus, where gradients vani

arXiv:2604.11857v1 Announce Type: new Abstract: Catalytic quantum error correction (CQEC) recovers quantum states via catalytic covariant transformations but requires full knowledge of the target state. We introduce \emph{blind CQEC}, which estimates the target from the noisy output alone before ca

arXiv:2604.11858v1 Announce Type: new Abstract: We consider symmetries and reduction in non-relativistic many-body quantum mechanics, with the aim of identifying physically meaningful observables in systems such as molecules and crystalline solids. To this end, we propose a unified framework based

arXiv:2604.11864v1 Announce Type: new Abstract: We present a parametrization of density matrices (mixed states) in a finite-dimensional Hilbert space $\mathbb{C}^n$, particularly suited to the description of their time evolution as open quantum systems governed by GKLS dynamics. A generic (non-dege

arXiv:2604.11872v1 Announce Type: new Abstract: We provide a pedagogical introduction to eigenstate thermalization. This phenomenon, which occurs in generic systems, allows one to understand why thermalization takes place in isolated quantum systems under unitary dynamics. We motivate eigenstate th

arXiv:2604.11876v1 Announce Type: new Abstract: Closed chaotic quantum systems relax after a quench into a Gibbs ensemble. At late times, the relaxation speed is determined by their conservation laws and hydrodynamics. As a result, there exist pairs of initial states which thermalize to the same en

arXiv:2604.11878v1 Announce Type: new Abstract: Processes with indefinite causal order (ICO), such as the quantum switch, are an emerging resource for quantum tasks and a fundamental test bed for studies of temporal correlations in quantum mechanics. A limitation of past photonic implementations of

arXiv:2604.11897v1 Announce Type: new Abstract: We calculate the response of an Unruh--DeWitt detector in a 2+1d spacetime that contains a BTZ black hole in a superposition of locations. Upon performing a Quantum Reference Frame (QRF) transformation, this can also be seen as a detector in a superpo

arXiv:2604.11900v1 Announce Type: new Abstract: Programmable quantum hardware provides an emerging platform for exploring and controlling non-unitary quantum dynamics through measurement-based operations. In this work, we introduce feedback-directed circuit architectures that integrate spatially st

arXiv:2604.11910v1 Announce Type: new Abstract: Quantum correlations in networks with independent sources have revealed novel forms of nonclassical behavior. While entanglement in the sources is a necessary ingredient, the role played by entanglement in the measurements remains largely unexplored.

arXiv:2604.11952v1 Announce Type: new Abstract: Complexity class containments involving interactive proof classes are famously nonrelativizing: although $\mathsf{IP} = \mathsf{PSPACE}$, Fortnow and Sipser showed that that there exists an oracle relative to which $\mathsf{coNP} \not\subseteq \mathsf

arXiv:2604.11963v1 Announce Type: new Abstract: Quantum error correction assumes that all syndrome activations represent errors requiring correction. We present evidence from 756 QEC runs across three IBM Eagle r3 processors that this assumption is wrong. The hardware exhibits sub-Poissonian syndro

arXiv:2604.11968v1 Announce Type: new Abstract: We introduce a two state vector formalism of quantum mechanics by generalizing Bell's hidden variable model to higher dimensions and by attributing a physical significance (a state evolving backward in time) to the hidden variable. A simple determinis

arXiv:2604.12050v1 Announce Type: new Abstract: We explore here how to generate a two-mode squeezed output using reservoir engineering in a double-cavity optomechanical system coupled to a common mechanical resonator. Such hybrid platforms are experimentally accessible in electro-optomechanical int

arXiv:2604.12094v1 Announce Type: new Abstract: I argue that there is a straightforward way to understand the occurrence of wavefunction collapses or 'quantum events' in relational approaches to quantum mechanics: we necessarily encounter a discontinuity in our description when a system interacts w

arXiv:2604.12106v1 Announce Type: new Abstract: Rydberg atomic receivers have recently emerged as a promising platform for radio-frequency (RF) sensing and reception due to their intrinsic broadband response and calibration-free operation. Most existing receivers rely on four-level ladder-type elec

arXiv:2604.12131v1 Announce Type: new Abstract: The short-path quantum algorithm introduced by Hastings (Quantum 2018, 2019) is a variant of adiabatic quantum algorithms that enables an easier worst-case analysis by avoiding the need to control the spectral gap along a long adiabatic path. Dalzell,

arXiv:2604.12141v1 Announce Type: new Abstract: We review the ideas of how random matrix theory has to be properly applied to quantum physics; particularly we focus on how the spectrum has to be properly prepared and the random matrix correctly identified before the random matrix and the physical e

arXiv:2604.12142v1 Announce Type: new Abstract: Strongly correlated materials are a natural target for fault-tolerant quantum computers, but they require tools beyond those developed for molecules. Electronic wavefunctions vary rapidly near nuclei yet remain delocalized across many unit cells, and

arXiv:2604.12157v1 Announce Type: new Abstract: Transferring the information stored in the expansion coefficients of a multi-qubit state to the coefficients of a continuous-variable state is an important protocol for communicating quantum information. It was shown in previous work how to transfer a

arXiv:2604.12186v1 Announce Type: new Abstract: We develop a quantum message-passing framework for factor graphs over finite abelian groups. Our starting point is the task of discriminating between a collection of quantum states indexed by the elements of a finite abelian group $\mathcal{G}$ whose

arXiv:2604.12187v1 Announce Type: new Abstract: We show that averaging matter dynamics over stochastic gravitational fluctuations gives rise to a complex velocity field \(\eta_{\mu} = \pi_{\mu} - i u_{\mu}\) living as a section of the pullback bundle \(E = \pi_{2}^{*}(T^{*}M)\to \mathcal{C}\times M

arXiv:2604.12224v1 Announce Type: new Abstract: This work investigates the dynamics of a charged particle in a uniform magnetic field within the Bohm--Madelung formulation of quantum mechanics. In this representation, the stationary Schrodinger equation separates into coupled amplitude and phase eq

arXiv:2604.12256v1 Announce Type: new Abstract: Quantum circuit simulation is crucial for the development of quantum algorithms, particularly given the high cost and noise limitations of physical quantum hardware. While full-state quantum circuit simulation is commonly employed for prototyping and

arXiv:2604.12261v1 Announce Type: new Abstract: The path toward practical superconducting quantum processors requires the integration of a large number of high-performance qubits. Modular architectures could offer a way to address the scaling limitations of monolithic designs by partitioning a larg

arXiv:2604.12267v1 Announce Type: new Abstract: The notion of Shannon entropy is crucial for the theory of classical information. In quantum information theory, an analogous key role is played by the von Neumann entropy: quantum information processing is closely related to entropy dynamics. This re

arXiv:2604.12272v1 Announce Type: new Abstract: Entanglement-based quantum key distribution (QKD) relies on the distribution of high-fidelity maximally entangled Bell states, typically generated via spontaneous parametric down-conversion (SPDC). In practical systems, unwanted relative phases arise

arXiv:2604.12276v1 Announce Type: new Abstract: A quadratic well plays a central role in a wide variety of modern physical theories and applications. In this work, we investigate many-body dynamics in a quadratic well, using an Ising chain as a paradigmatic example. In contrast to a uniform Ising c

arXiv:2604.12279v1 Announce Type: new Abstract: We numerically optimized a scheme for a neutral atom Rydberg blockade symmetric controlled-Z (CZ) gate to increase its robustness to variations in the Rabi frequency. This gate scheme uses analytically defined phase profiles of the laser pulse and dem

arXiv:2604.12296v1 Announce Type: new Abstract: One of the promising applications of digital quantum processors is the simulation of many-body quantum systems. They have been already used to investigate several ergodicity violating mechanisms, which were initially discovered in synthetic quantum ma

arXiv:2604.12316v1 Announce Type: new Abstract: The kicked rotor provides a simple yet powerful model for introducing many of the central concepts of classical and quantum chaos. Despite its apparent simplicity, it exhibits rich dynamical behavior and has found applications across a wide range of f

arXiv:2604.12323v1 Announce Type: new Abstract: Quantum metrology promises phase sensitivity surpassing the shot-noise limit by exploiting entanglement and photon-number correlations. NOON states-maximally path-entangled $N$-photon superpositions $(|N,0\rangle + |0,N\rangle)/\sqrt{2}$ -achieve the

arXiv:2604.12330v1 Announce Type: new Abstract: Quantum computers solve intractable problems which classically require an exponentially long time to compute. With the development of large-scale experiments that claim quantum advantage, a vital issue has now emerged. What are the errors, and how do

arXiv:2604.12338v1 Announce Type: new Abstract: High-dimensional quantum systems offer a number of advantages in larger information capacity, stronger noise resiliency, higher improved efficiency and accuracy over the qubit systems. In quantum communication the maximally entangled states will inevi

arXiv:2604.12345v1 Announce Type: new Abstract: The quantum kicked top (QKT) is one of the most widely studied models in quantum chaos, providing a minimal yet powerful framework for exploring the relationship between classical nonlinear dynamics and quantum behavior. Unlike many chaotic systems wi

arXiv:2604.12347v1 Announce Type: new Abstract: Self-healing is the ability of a wave packet to spontaneously restore its spatial profile after scattering. As an emergent feature of non-unitary dynamics, it has attracted significant interest in non-Hermitian physics. Here, we systematically investi

arXiv:2604.12354v1 Announce Type: new Abstract: One intriguing property of non-Hermitian systems is the breakdown of adiabatic theorem and chiral state conversion as the system dynamically encircles exceptional points. However, the subtle dependence of the chiral dynamics on the loop geometry, the

arXiv:2604.12361v1 Announce Type: new Abstract: We present a comprehensive theoretical analysis of ultrafast entanglement generation between two Rydberg-blockaded atoms, explicitly accounting for realistic laser noise. Using femtosecond Gaussian pulses as a baseline, we systematically evaluate Bell

arXiv:2604.12369v1 Announce Type: new Abstract: Out-of-Time-Order Correlators (OTOCs) quantify quantum information scrambling, but their connection to localized phase-space structures, such as chemical transition states, requires formal development. We derive a leading-order semiclassical expansion

arXiv:2604.12381v1 Announce Type: new Abstract: The effectiveness of quantum illumination (QI) of a lossy target is investigated in a realistic setting in which the signal sequentially interacts with a noisy environment and the target. The target is considered at a temperature distinct from its sur

arXiv:2604.12395v1 Announce Type: new Abstract: Linear optical spectra of molecular aggregates are often approximated by classical optics methods such as the discrete-dipole approximation (DDA), coherent exciton scattering (CES), and coherent potential approximation (CPA), where the only quantum-me

arXiv:2604.12410v1 Announce Type: new Abstract: We analyze the Schwarz inequality and its generalizations, as well as inequalities resulting from the Jensen inequality. They are used in quantum theory to derive the Heisenberg-Robertson (HR) and Schroedinger-Robertson (SR) uncertainty relation for t

arXiv:2604.12441v1 Announce Type: new Abstract: Model-independent estimation of the properties of quantum states is a central challenge in quantum technologies, as experimental imperfections, drifts, and imprecise models of the actual quantum dynamics inevitably hinder accurate reconstructions. Her

arXiv:2604.12450v1 Announce Type: new Abstract: We analytically describe the dynamically separated $\mathbb{Z}_{2}$ skin channels (wavepacket evolutions) under periodic boundary condition (PBC) in non-Hermitian systems with anomalous time-reversal symmetry (ATRS), by combining the semiclassical wor

arXiv:2604.12464v1 Announce Type: new Abstract: We present an introductory review of nonergodic dynamics in interacting many-body quantum systems, focusing on the phenomenon of many-body localization (MBL). We describe aspects of MBL and summarize the evidence for a crossover from the ergodic to th

arXiv:2604.12465v1 Announce Type: new Abstract: We demonstrate the Parity Architecture on quantum hardware, using the quantum Fourier transform (QFT) as a benchmark. As a result, a record performance in both fidelity and qubit count is achieved using quantum processors with a native CZ-based instru

arXiv:2604.12476v1 Announce Type: new Abstract: The quantum kernel method, a promising quantum machine learning algorithm, possesses substantial potential for demonstrating quantum advantage. Although the majority of the quantum kernel is constructed in the context of gate-based quantum circuits, i

arXiv:2604.12516v1 Announce Type: new Abstract: We use the configuration-space Faddeev formalism to study scattering of three particles in the double continuum where all particles are free. All scattering processes, starting from and ending in both single and double continua, are collected in a uni

arXiv:2604.12549v1 Announce Type: new Abstract: Feedback-controlled electromigration (FCE) enables precise regulation of atomic migration by carefully optimizing multiple experimental parameters. However, manually fine-tuning these parameters poses significant challenges. This study investigated th

arXiv:2604.12560v1 Announce Type: new Abstract: Fault-tolerant quantum computers (FTQCs) based on surface codes and lattice surgery have been widely studied, and there is strong demand for a framework that can identify logical operations with low space-time cost, verify their functionality and faul

arXiv:2604.12576v1 Announce Type: new Abstract: The $p_3$-PPT criterion is an experimentally viable relaxation of the well-known positive partial transposition (PPT) criterion for the certification of quantum entanglement. Recently, it has been generalized to various families of entanglement criter

arXiv:2604.12577v1 Announce Type: new Abstract: Quantum key distribution protocols based on the quantum eraser phenomenon offer an operational advantage: automatic identification of matching and mismatching encoding choices through interference, eliminating basis reconciliation over public channels

arXiv:2604.12629v1 Announce Type: new Abstract: We investigate the mutual information harvesting of two circularly accelerated detectors that interact with the massless scalar fields near a reflecting boundary. We consider that the two detectors share a common rotational axis with the same accelera

arXiv:2604.12635v1 Announce Type: new Abstract: Instantaneous Quantum Polynomial-time (IQP) circuits are a candidate for demonstrating near-term quantum advantage, as their sampling task is believed to be classically hard in the ideal theoretical setting under standard complexity-theoretic assumpti

arXiv:2604.12646v1 Announce Type: new Abstract: We demonstrate that quantum light statistics can be used to control strong-field ionization at the tunneling step. Using a bichromatic linearly polarized field composed of a strong coherent driver and a weak bright squeezed vacuum (BSV), we show throu

arXiv:2604.12661v1 Announce Type: new Abstract: Quantum states of light are central resources for quantum communication, networking, and photonic information processing. In many quantum emitters, coherent internal dynamics arising from intrinsic or field-induced level splittings imprint a determini

arXiv:2604.12684v1 Announce Type: new Abstract: Orthogonal geometric constructions are the basis of many many quantum error-correcting codes (QEC), but strict orthogonality constraints limit design flexibility and resource efficiency. We introduce a quasi-orthogonal geometric framework for stabiliz

arXiv:2604.12690v1 Announce Type: new Abstract: Quantum graphs are a paradigmatic model for quantum chaos as well as for spectral theory. We give a concise didactical introduction to quantum graphs, or Schr\"odinger Hamiltonians on metric graphs, with a focus on results related to quantum cha

arXiv:2604.12707v1 Announce Type: new Abstract: One of the fundamental manifestations of classical chaos is exponential sensitivity to initial conditions that is, two trajectories starting from nearly identical initial states diverge exponentially over time. This behavior is quantified by the Lyapu

arXiv:2604.12718v1 Announce Type: new Abstract: Ising machines are physical platforms designed to minimize the energy of classical Ising Hamiltonians, yet accessing specific excited states remains an open challenge of both fundamental and practical relevance. In this letter we show that a network o

arXiv:2604.12724v1 Announce Type: new Abstract: We propose a method to test whether a photonic 3D QRNG works according to the underlying theory, thereby generating highly incomputable/unpredictable sequences of random digits. The test relies on undoing the unitary evolution realized by the 3D QRNG.

arXiv:2604.12739v1 Announce Type: new Abstract: Decoherence and dissipation, arising from unavoidable interactions with the environment, can exert a dual influence on transport in physical systems, suppressing coherent propagation while inducing diffusion and mitigating localization in disordered s

arXiv:2604.12741v1 Announce Type: new Abstract: Mesoscopic devices, with system sizes in the range of several to several dozens wavelengths, represent paradigmatic model systems for the observation of quantum chaotic behaviour based on semiclassical concepts. Those electronic and photonic billiard

arXiv:2604.12745v1 Announce Type: new Abstract: In quantum systems with a classical limit, advanced semiclassical methods provide the crucial link between phase-space structures, reflecting the distinction between chaotic, mixed or integrable classical dynamics, and the corresponding quantum proper

arXiv:2604.12763v1 Announce Type: new Abstract: We present a real-time path-integral formulation of the quantum Fisher information for dynamical parameter estimation. For pure states undergoing unitary evolution, we show that the quantum Fisher information can be expressed as a connected symmetrize

arXiv:2604.12784v1 Announce Type: new Abstract: Recent years have witnessed tremendous progress in developing a fine-grained low-dimensional holographic correspondence, specifically the construction of quantum mechanical boundary theories as holographic duals of two-dimensional gravity. In these de

arXiv:2604.12796v1 Announce Type: new Abstract: The role of complex numbers in quantum theory extends beyond mathematical convenience, having recently been formalized as a resource under the framework of the resource theory of imaginarity. Operationally, imaginarity translates into using fewer reso

arXiv:2604.12808v1 Announce Type: new Abstract: We study the distinguishability of quantum states under local operations with classical communication (LOCC), separable, and positive-partial-transpose (PPT) measurements, focusing on locally diagonal orthogonally invariant (LDOI) states -- those inva

arXiv:2604.12823v1 Announce Type: new Abstract: In this article, we find a theorem that gives a relation between the maximal fidelity of teleportation and the concurrence of the inseparable $X$ state used as a quantum channel in this process. Furthermore, we evaluate the concurrence of the output s

arXiv:2604.12838v1 Announce Type: new Abstract: We experimentally observe a new type of quantum-path interference, in two-dimensional(2D-QPI), in high-harmonic generation (HHG) driven by an orthogonally-polarised highly-bichromatic field. This regime is marked by comparable intensities of the two o

arXiv:2604.12841v1 Announce Type: new Abstract: Fast, scalable decoding architectures that operate in a block-wise parallel fashion across space and time are essential for real-time fault-tolerant quantum computing. We introduce a scalable AI-based pre-decoder for the surface code that performs loc

arXiv:2604.12947v1 Announce Type: new Abstract: The tunable interaction between stationary quantum bits and propagating modes of light allows for the encoding of quantum information in the state of itinerant photons. This ability fulfills a central requirement for quantum networking, enabling quant

arXiv:2604.12976v1 Announce Type: new Abstract: Through semiclassical methods the subject of quantum chaos motivates and depends on Hamiltonian chaos research. Presented here is a selection of Hamiltonian chaos topics that in this way get directly related to any of a variety of quantum chaos resear

arXiv:2604.12982v1 Announce Type: new Abstract: While Quantum Key Distribution (QKD) has been proven in lab environments, large-scale implementation requires integration with existing infrastructure. This paper proposes an opportunistic QKD framework that takes advantage of idle spectral capacity,

arXiv:2604.12985v1 Announce Type: new Abstract: The emergence of Cryptographically Relevant Quantum Computers (CRQCs) presents a critical threat to classical cryptographic systems, particularly widely adopted protocols such as RSA, Diffie-Hellman (DH), and Elliptic Curve Cryptography (ECC). Given t

arXiv:2604.13022v1 Announce Type: new Abstract: The Energy Conserving Descent (ECD) algorithm was recently proposed (De Luca & Silverstein, 2022) as a global non-convex optimization method. Unlike gradient descent, appropriately configured ECD dynamics escape strict local minima and converge to a g

arXiv:2604.13026v1 Announce Type: new Abstract: We study the computational complexity of 2-local Hamiltonian problems generated by a positive-weight symmetric interaction term, encompassing many canonical problems in statistical mechanics and optimization. We show these problems belong to one of th

arXiv:2604.13027v1 Announce Type: new Abstract: Many-body cages have very recently emerged as a general route for nonergodic behaviour in quantum matter. Here, we show that new types of many-body cages can be engineered in Floquet circuits with the potential to realize novel nonequilibrium quantum

arXiv:2604.13032v1 Announce Type: new Abstract: In this work we explore the potential of implementing an optical quantum optimizer using non-linear optics, specifically using sum-frequency generation and/or two photon absorption. This proposal uses Zeno effects to enforce independence constraints a

arXiv:2604.13033v1 Announce Type: new Abstract: We construct for a Schur concave function $f$ on the set of quantum states a tight upper bound on the difference $f(\rho)-f(\sigma)$ for a quantum state $\rho$ with finite $f(\rho)$ and any quantum state $\sigma$ $m$-partially majorized by the state $

arXiv:2604.01455v1 Announce Type: cross Abstract: Large language models (LLMs) are increasingly explored for NP-hard combinatorial optimization problems, but most existing methods emphasize feasible-instance solution generation and do not explicitly address infeasibility detection. We propose an in

arXiv:2604.11855v1 Announce Type: cross Abstract: Lattice quasi-periodicity is easily realized with ultracold atoms in optical lattices and has been used to study delocalization-localization transition at low dimensions. Models with true disorder, however, remains largely unrealized in experiments.

arXiv:2604.11870v1 Announce Type: cross Abstract: Programmable arrays of neutral Rydberg atoms are one of the leading platforms today for scalable quantum simulation and computation. In these systems, the dipole-dipole interactions between the individual atoms, or qubits, typically result in binary

arXiv:2604.11984v1 Announce Type: cross Abstract: Nonlinear light-matter interaction and, in particular, high-harmonic generation (HHG) are fundamentally interesting and frequently discussed as versatile probes of quantum materials with potential for optical information processing applications. Mea

arXiv:2604.12111v1 Announce Type: cross Abstract: By an idealized quantum mechanical model, we formally describe the dispersion of nonretarded electromagnetic surface waves that express charge density oscillations near a fixed plane in three spatial dimensions (3D) at zero temperature. Our goal is

arXiv:2604.12393v1 Announce Type: cross Abstract: In this paper we reexamine the definition of parafermions and parabosons by means of Green's triple relations, and extend these relations by including a parity operator $P$ which is also determined by means of triple relations. As a consequence, we

arXiv:2604.12409v1 Announce Type: cross Abstract: This chapter gives an overview of transport problems where chaotic dynamics of the system plays a crucial role. We begin with single-particle transport problems and then come to conservative and then dissipative systems of identical particles, which

arXiv:2604.12544v1 Announce Type: cross Abstract: We investigate electron paring in two-dimensional electron systems mediated by the vacuum fluctuations of a quantized magnetic flux generated by the inductor of an LC resonator. The interaction induces long-range attractive interactions between angu

arXiv:2604.12605v1 Announce Type: cross Abstract: A time-dependent theory for the interactions between spatially separated lossy cavities in a homogeneous background medium using quantized quasinormal modes (QNMs) is presented. The cavities interact via a bath of traveling photons, described by non

arXiv:2604.12664v1 Announce Type: cross Abstract: We investigate the optical response of a conduction electron in a helically twisted mesoscopic medium containing a screw dislocation and a uniform torsional background, in the presence of an axial magnetic field and an Aharonov--Bohm flux. We show t

arXiv:2604.12754v1 Announce Type: cross Abstract: Long-range interactions can fundamentally reshape the low-energy properties of low-dimensional quantum matter, altering both continuous symmetry breaking and topological phenomena. However, their impact on the quantum criticality separating these re

arXiv:2604.12824v1 Announce Type: cross Abstract: All-optical generation of pure spin current -- the flow of spin in the absence of a corresponding charge flow -- relies on a symmetry based compensation of valley charge. The 2d $d$-wave altermagnets, ideal spintronics materials due to a very low sp

arXiv:2604.12907v1 Announce Type: cross Abstract: Hilbert space fragmentation refers to exponential growth in the number of dynamically disconnected Krylov sectors with system size. It is taken as evidence of ergodicity breaking, since conventional symmetries generate at most a polynomial number of

arXiv:2604.12939v1 Announce Type: cross Abstract: In Hermitian impurity scattering, each isolated late-time exponential is the fingerprint of a bound state. We show that this correspondence breaks down in non-Hermitian bands. For a single impurity in a non-Hermitian lattice, the late-time signal is

arXiv:2604.13003v1 Announce Type: cross Abstract: Neutrino billiards serve as a model system for the study of aspects of relativistic quantum chaos. These are relativistic quantum billiards consisting of a spin-1/2 particle which is confined to a planar domain by imposing boundary conditions on the