July 23, 2026

Fermionic pairs, from the surface to the bulk

Fermion pairing underlies collective quantum phenomena across widely different forms of matter. In extended systems such as ultracold Fermi gases, pairing is commonly understood through the BCS--BEC crossover, where the pair size evolves from large, overlapping Cooper pairs to tightly bound dimers. In finite systems such as atomic nuclei, superconducting grains and quantum d...

Microwave-driven same-species sympathetic cooling for trapped ions

Sympathetic cooling of data qubits by coolant ions is an essential technique for trapped-ion quantum computing. Conventionally a second ion species is used, requiring additional lasers and complicating optical setups. We propose a scheme for sympathetic cooling using the same species and test it for ^(43)Ca^+ ions. Pulsed sideband cooling and ion addressing are implement...

Lattice quantum electrodynamics of a molecular emitter in a topological gap

Engineering the photonic environment using lattices of coupled resonators, which we refer to as lattice quantum electrodynamics (QED), provides a route to control both the spontaneous emission of individual quantum emitters and the photon-mediated interactions between them. Here we introduce an optical lattice QED platform based on individual dibenzoterrylene (DBT) molecules...

Observable Geometry for Effective Quantum Circuits

We study redundancy and effectiveness of Variational Quantum Circuits via algebraic and geometric views of Lie groups. Considering unitary transformations acting on Hermitian observables, a stabilizer group decomposition is given. Subsequently, we identify the Hermitian orbit with a quotient space of a symmetric space. Through this connection, we characterize the effective c...

Biased-noise qubits: a guide to efficient fault-tolerance using the hierarchy of errors

Qubits with strongly biased noise, in which phase-flip errors are orders of magnitude more frequent than bit-flips, arise both naturally, as in electron and nuclear spins, and by engineering, as in stabilized cat qubits. This noise structure holds the promise of reducing the daunting hardware overhead of fault-tolerant quantum computing, but exploiting it requires physical o...

Learning to Decode Quantum LDPC Codes via Cluster-Based Sequential Belief Propagation

Belief-propagation (BP) decoding for quantum low-density parity-check (QLDPC) codes is attractive due to its low complexity, but its performance is often limited by short cycles, degeneracy, and convergence failures. Recently, reinforcement-learning-based sequential variable-node (VN) scheduling (RL-S) was shown to improve BP decoding by learning state-dependent update order...

Physics-Informed Graph Neural Networks for Surface Code Decoding via Discrete Exterior Calculus

We introduce a physics-informed graph neural network decoder for the surface code. A discrete Poisson equation on the syndrome graph acts as a hard inductive bias on which a graph encoder learns syndrome-adaptive edge weights. A differentiable solver returns the node potentials and the associated edge current. Our central observation is that the logical-error signal is not c...

PN-QNN: Harnessing Physical Noise as a Native Regularizer in Photonic Hybrid Quantum Neural Networks

Physical noise in near-term quantum hardware is usually treated as a nuisance to suppress. We ask whether it can instead act as a hardware-native regularizer for photonic hybrid quantum-classical neural networks (PHQCNNs), analogous to noise-injection regularization in classical deep learning. Using Quandela's Perceval simulator and the MerLin framework, we build PHQCNNs for...

Identifying local unitary equivalence based on reduction of quantum states

Local unitary equivalence is central to entanglement quantification and classification. Identifying the local unitary equivalence remains a formidable challenge. We address this problem for a class of quantum states with one highly degenerate eigenvalue and the rest non-degenerate simple eigenvalues that are pivotal to structured resources in quantum resource theory. We intr...

DQAOA-GPT: AI-Accelerated Distributed Quantum Optimization for Combinatorial Problems

While combinatorial optimization problems are central to many scientific and engineering applications, their solution remains challenging due to exponentially large search spaces. Variational quantum algorithms offer a promising route for tackling such problems, yet their practical performance is limited by repeated quantum circuit evaluations and classical parameter updates...

Quantum Kernels and the Cross-Section of Stock Returns: Anatomy of a Vanishing Advantage

Do quantum kernels improve cross-sectional stock return prediction? We run a controlled horse race on the Chinese A-share market in which a quantum fidelity kernel, a projected quantum kernel, and a classical RBF control share identical training subsamples, solver, and tuning budgets, so that only the kernel is exchanged. On the main evaluation -- a point-in-time universe an...

A Multiclass Quantum Aligned Centroid Kernel

Kernel methods are powerful tools in machine learning but commonly used full-Gram kernels face three key limitations: (1) quadratic scaling with training set size; (2) the use of fixed, non-trainable kernels; and (3) the absence of an intrinsic formulation for multiclass classification. We present McQuack, a trainable quantum kernel method for multiclass problems that achiev...

Exact Closed-Form Quantum Correlations of Maximally Entangled Qudit States under Arbitrary Non-Markovian Pure Dephasing

We study the time evolution of entanglement and quantum discord for a pair of maximally entangled qudits of arbitrary dimension d under non-Markovian pure dephasing, using the exact solution of the independent boson model. Because this solution requires no Born--Markov, Lindblad, or rotating-wave approximation, every result reported here follows directly from the exact dyn...

New Framework Uses Quantum Geometry to Help Quantum AI Systems Remember What They Learn

Statevector-Referenced Geometry Survival of a Four-Qubit ZZ Quantum Kernel on IBM Quantum Hardware: A Fixed-Subset Diagnostic Across Three Execution Configurations

Quantum-kernel methods encode a dataset's geometry in a Gram matrix, so learning claims on hardware kernels assume the intended geometry survives execution. We measure that survival for one frozen four-qubit ZZ feature-map kernel on N=24 real indoor air-quality windows, reconstructed on ibm_fez (1024 shots per circuit) under baseline, dynamical decoupling alone, and gate t...

Anticoncentration of the Permanent in Ginibre Ensembles

Let K∈{R,C,H}, put β=dim_RK, and let G_n^K be an n×n matrix with i.i.d. standard K-Gaussian entries, namely a standard K-Ginibre matrix. We prove that the normalized row-ordered permanent W_n^K=per_KG_n^K/√(n!) has...

Toroidal Transitions in Hydrogenic and Alkali Atoms

In addition to electric and magnetic multipoles, the expansion of current density also yields toroidal terms, a lesser-known family of multipoles. A recent proposal, I. Kuprov et al., Science Adv. 8 abq6751 (2022), explores the possibility of a direct observation of optical toroidal transitions in hydrogen and alkali atoms in the presence of a large magnetic field...

Quantinuum Appoints New Chief Legal Officer and Chief People Officer

Hitachi, Intel and AIST Launch Silicon Quantum Computing Project Backed by Japanese Government

Efficiently Simulable Pauli Correlation Encoding

Pauli Correlation Encoding (PCE) is a heuristic framework for binary optimisation that encodes classical variables into many-body Pauli observables. While PCE requires fewer qubits than other approaches, it relies on estimating a large number of Pauli expectation values whose signs determine the variables' values, which can incur substantial measurement overhead. Here, we in...

Qoreo: Choreographic Programming for Quantum Distributed Systems

Programming distributed quantum systems requires multiple actors to coordinate precise sequences of quantum operations, classical communication, and entanglement generation. Writing such protocols directly as distributed processes is tedious and error-prone, and subtle mismatches can cause deadlock or silently incorrect quantum states. We present Qoreo, a choreographic progr...

Arnold--Nielsen Geometry for Complexity-Deformed Noncommutative Transport

We deform the Carlen--Maas--Wirth framework for noncommutative dynamical optimal transport by an Arnold--Nielsen type complexity operator. A positive state-independent operator G compatible with the Hilbert bimodule structure of a noncommutative differential calculus ∂colonM→Hcal can be absorbed into the calculus itself, ∂_G:=G^(1/2)∂. The...

Collective Electronic Entanglement via Infrared Cavity-Induced Vibronic Transduction

Polaritonic architectures seek to engineer molecular properties by hybridizing localized degrees of freedom with delocalized optical cavity fields. However, scaling laws impose a severe bottleneck on N-molecule collective strong coupling: because each molecule contributes only a fractional share to the collective state, localized responses undergo O(1/N) ensemble dilution. W...

Quantum-state block texture and its quantification

Quantum-state texture (QST) is an emerging quantum resource that has garnered increasing attention amid advances in quantum theory. In this work, we generalize the QST to quantum-state block texture (QSBT). This generalization provides profound operational interpretations for quantifying the advantages of quantum states in quantum information processing. We pioneer an altern...

Angular Momentum Quantization of a Charge-flux Composite: Quantum Electrodynamic Approach

The fractional angular momentum of a two-dimensional charge-flux composite is a well-established phenomenon usually derived from a semiclassical Hamiltonian. However, when the composite is treated as an isolated system in free two-dimensional space, the fundamental rotational and reflection symmetries of the O(2) group demand that its total angular momentum is strictly qua...

Dynamical redistribution of quantum resources in tree-level Bhabha scattering

The fundamental interactions governed by quantum electrodynamics (QED) are intrinsically rich in quantum resources, yet how these resources dynamically redistribute during relativistic scattering is still not fully understood. In this work, we systematically investigate the tree-level Bhabha scattering process (e^- e^+ \rightarrow e^- e^+) within the framework of quantum res...

Entanglement dynamics through electromagnetic interactions in single-electron traps

We study the dynamics of quantum entanglement between two harmonically trapped electrons interacting via the electromagnetic force. Starting from two-mode Gaussian states at thermal equilibrium, we make use of the covariance matrix formalism in order to compute the logarithmic negativity of the evolved state as a quantitative measure of entanglement. We analyze two initial c...

Coupling phase interference effects in a multimode cavity magnonics system

Coupling phases play a decisive yet often overlooked role in cavity magnonics, particularly in complex multimode systems. Here, we investigate phase-mediated interference effects in a cavity magnonics system comprising a four-post re-entrant microwave cavity coupled to Yttrium Iron Garnet (YIG) spheres. Using an input-output model that explicitly accounts for both internal a...

Mesoscopic mechanical superpositions by gluing individual quantum systems

We propose a protocol for preparing mechanical Schrödinger kittens -- mesoscopic quantum superpositions of coherent motional states of an optically levitated nanoparticle -- by adhering single electron time-bin states to its surface. Over short protocol timescales, coherence of the mesoscopic superposition survives the dominant decoherence mechanisms afflicting levitated sys...

Intermittency in Quantum Graviton-Phonon Conversion

A graviton can be converted into a phonon in a resonant bar detector. First-order perturbation theory predicts a strong enhancement of this conversion for coherent and squeezed graviton states, but the probability can exceed unity when the coherent or squeezing parameter is large. Since a conversion probability must satisfy the unitarity bound, we solve the graviton-phonon q...

Schrödinger's real-valued equation revisited

The Schrödinger equation can be rewritten as a second-order equation for a single real-valued scalar field. Taken at face value, however, this one-field reduction obscures several local structures of quantum mechanics: the Born density and current, the role of momentum as a generator, and the usual derivation of the uncertainty relation. We argue that these difficulties do n...

Slack-Free Deep-Unfolded Combinatorial Optimization Solver for Inequality Constraints

Quantum annealing (QA) is used to solve combinatorial optimization problems (COPs). When COPs are implemented on quantum annealers, they are typically encoded as quadratic unconstrained binary optimization (QUBO) problems, but constraint encodings often increase the number of qubits and the embedding overhead. This issue is particularly important for COPs with inequality con...

A framework for separating dephasing from decoherence in matter-wave Bell interferometers

Matter-wave Bell interferometers provide a sensitive probe of mass-dependent decoherence in entangled quantum systems. The degree of entanglement is obtained from the Bell-correlation amplitude of this interferometer. For observing potential mass-dependent decoherence, a reliable interpretation of any observed reduction in the Bell correlation amplitude is required, which de...

Construction of a Class of Communication-Efficient Quantum Secret Sharing Schemes

Quantum secret sharing is a fundamental technique in quantum cryptography. However, in practical quantum networks, it still faces several bottlenecks, such as high quantum communication cost and low transmission efficiency. To reduce the communication cost, ramp quantum secret sharing schemes have been proposed in existing studies. Nevertheless, intermediate sets in such sch...

Propagation dynamics of high-gain vortex beams in symmetry-broken media via forward and backward three-wave mixing

In recent years, vortex light, a distinctive form of structured light, has attracted considerable attention owing to its unique properties and the rich physical phenomena arising from its interaction with matter. In this paper, we investigate the propagation dynamics of vortex beams in a symmetry-broken three-level system based on forward and backward three-wave mixing (TWM)...

Nonreciprocal phonon blockade in spin quadratic optomechanical systems

We propose a scheme for achieving nonreciprocal phonon blockade in a quadratic optomechanical (QOM) system consisting of two spinning resonators near-field coupled to a nanomechanical oscillator. Due to the Sagnac-Fizeau effect, pump fields propagating in opposite directions experience distinct effective detunings,thereby leading to asymmetric intracavity intensities. Throug...

A reduction scheme for general-order Ising-like Hamiltonians in quantum heuristic solvers

The Ising model is ubiquitous in various optimization problems but notoriously difficult to solve due to combinatorial explosion. In view of this, Hamiltonian reduction is a useful preprocessing technique for reducing the effective problem size before applying heuristic solvers. However, existing reduction techniques mainly target second-order Ising models, whereas many pseu...

Emergent boundary-memory from unitarity constraints in a minimal two interacting quantum particles

We construct a simple model of two particles mutually attracting/repulsing in a one-dimensional lattice and investigate the corresponding dynamics. We show that enforcing reversible unitary evolution on a minimal direct-motion interaction rule necessarily gives rise to emergent boundary-memory and non-trivial dynamics. Remarkably, the resulting boundary-memory leads to event...

A Multi-Resolvent Hierarchy for the ETH Smooth Function

The eigenstate thermalization hypothesis (ETH) provides a statistical description of thermalization in isolated quantum many-body systems, yet the phenomenological smooth function f_O(E,ω) -- which controls the energy dependence of off-diagonal matrix elements -- lacks a systematic microscopic foundation. We develop a multi-resolvent hierarchy for the correlation cor...

Generation of vortex-squeezed light in a coherently prepared medium

In this Letter, we theoretically propose an alternative scheme for generating vortex optical squeezing, based on the Raman scattering process in a coherently prepared medium, distinct from approaches such as parametric down-conversion and four-wave mixing. Our analysis reveals that both the input control field and the generated signal field can exhibit squeezing upon adjusti...

Optimal Lower Bounds for Hamiltonian Simulation

For Hamiltonian H = Σ_j h_j, we prove asymptotically tight lower bounds on the gate and query complexities of simulating time evolution on a quantum computer. Our bounds hold for arbitrary term norms ‖h_j‖, time t, and trace-distance error ε. The matching upper bound (known as composite qDRIFT) consists of high-order Trotterization of the large terms and a rando...

Distributed Entanglement Distribution Using Multiple Entanglement Sources in WDM-based Quantum Optical Networks

Quantum network implementations using single spontaneous parametric downconversion (SPDC)-based broadband entangled photon pair source (EPPS) have been reported recently. Here, leveraging the wavelength-correlation between entangled photon pairs, the traditional wavelength division multiplexing (WDM) method is utilized to route photons based on their wavelengths. From single...

Multi-Criticality and RG Topology in the Charge-Kondo-Breakdown Scenario in the Cuprates

In this paper, we examine the dynamical charge-Kondo-breakdown scenario proposed for cuprate superconductors within the perspective of renormalization group (RG) topology. By analyzing the coupled RG flow equations governing the effective low-energy theory, we determine the fixed-point structure, stability properties, and global organization of the flow. We find that the put...

Energy Flux as an Entanglement Current in Moving-Mirror Radiation

In this work, we investigate the quantum entanglement properties of analog Hawking radiation produced by a moving mirror. Using two detector modes defined through window functions on a quantum field, we quantify the bipartite entanglement established between these modes. Our results reveal that the amount of entanglement accessible to the detectors increases when the mirror...

The Quantum Adiabatic Theorem for Non-Hermitian Dynamics

We establish a quantitative adiabatic estimate for a class of finite-dimensional non-Hermitian Schrödinger dynamics. The original non-Hermitian Hamiltonian is assumed to be diagonalizable with real spectrum and non-crossing eigenvalues. We then construct a dynamically compatible time-dependent metric operator, and its positive square root defines a Dyson map. The associated...

Structured-light-mediated hybrid entanglement between photon polarization and electronic orbital angular momentum

We propose a minimal quantum-optical scheme for generating hybrid entanglement between photon polarization and electronic orbital angular momentum in a semiconductor quantum disk. A spin--orbit structured two-photon state excites two channels in the same disk: a radiatively recombining zero-orbital-angular-momentum channel and a finite-orbital-angular-momentum channel that s...

Analytical Retrieval of Material Parameters in Monolayer Transition-Metal Dichalcogenides Based on a Solvable Exciton Model

We develop an analytical procedure to retrieve fundamental material parameters of monolayer transition-metal dichalcogenides from optical and magneto-optical exciton spectra, based on the solvable modified Kratzer model. The proposed retrieval procedure naturally consists of two complementary stages. In the first stage, explicit inversion formulas determine the quasiparticle...

Nuclear Quantum Effects as a Denoising Problem

Nuclear quantum effects are rigorously captured by imaginary-time path integrals, which map the quantum Boltzmann distribution onto a ring polymer of classical replicas. Yet the nuclear masses, the coupling to the environment, and the boundary conditions of the path remain hard-wired in the simulation or the trained model, even though this quantum context enters the path mea...

On the global well-posedness for the nonlocal Fokas-Lenells equation with the weighted Sobolev initial data on the line

We establish the global well-posedness of the Cauchy problem for the reverse space-time nonlocal Fokas-Lenells equation with the weighted Sobolev initial data q_0(x)∈H^3(R) ∩H^(2,1)(R) on the line. We develop the inverse scattering transform formulated via the associated Riemann-Hilbert problems to study this issue. A spectral uniformization tran...

On Solutions of the Killingbeck Potential and Clarifying Comments on a Related Analytical Approach

The work presents analytical solutions to the Schrodinger equation for the Killingbeck potential, a Hybrid model combining harmonic, linear and Coulomb terms, and which is also an approximate model of Yukawa-type potentials. The radial Schrodinger equation is solved by means of the series expansion method, thus yielding the exact expressions of both bound-states solutions an...

Zero Point Cryogenics Opens Chicago Hub to Support Quantum Computing Infrastructure

Northwestern University Researchers Demonstrate Quantum Entanglement Over Busy Telecom Fiber

Infleqtion Receives Three DOE Genesis Mission Projects for Quantum Computing and Sensing Research

Keyfactor Expands Partner Program for Post-Quantum Cryptography Readiness