July 21, 2026

QuantiSpect: A Structure-Aware Lightweight 3D CNN Pre-Decoder for Scalable Surface Code Quantum Error Correction

Real-time decoding is a critical bottleneck for large-scale fault-tolerant quantum computing. AI-based neural pre-decoders locally correct most physical errors before passing residual syndromes to a global decoder, enabling sub-microsecond latencies. However, existing architectures carry significant overhead from dense 3D convolutions. We present QuantiSpect, a lightweight 3...

Phase-Sensitive Benchmarking of Composite Quantum Gates with Chiral-Interference Circuits on Quantum Hardware

We construct and experimentally implement compact gate-native circuits that simulate the state-transfer interference underlying three- and four-level chiral-resolution protocols. Both models are encoded in a two-qubit register, with the enantiomer-dependent sign of one of the couplings simulated by a conditional-phase operation in the four-level circuit and by the sign of a...

Fixed Point Exploration For CV-QKD IR QC-MET-LDPC Toward Hardware Implementation

High-speed LDPC decoding is a major bottleneck in CV-QKD and motivates hardware acceleration with fixed-point arithmetic. This work compares SPA, MSA, and NMS under a unified low-SNR fixed-point framework using common graph, matrix, and quantization settings. Multiple formats are evaluated through FER, and average iterations. The results show that performance depends strongl...

Variational non-gaussian approach to interacting spin-boson models

We apply a hybrid variational framework to interacting spin-boson Hamiltonians, targeting regimes where simulations are limited by the unbounded bosonic Hilbert space and strong many-body correlations. The bosonic sector and spin-boson correlations are captured within a compact non-Gaussian variational manifold, while the minimized spin sector is obtained as the solution to...

Unifying Charge-Learnability Transitions in U(1)-Symmetric Quantum Circuits through Informational Power of Local Measurement

Charge-learnability transitions in monitored symmetric quantum circuits reveal how local measurement records acquire sufficient information to infer a conserved charge. Here we extend charge learnability to probabilistic weak measurements, for which the measurement probability and measurement strength are independently tunable. We find that the learnability phase boundary is...

On the use of the Belopol'skaya-Daletskii representation of a diffusion on a Riemann manifold to construct path integrals

We show that the Belopol'skaya-Daletskii formulation of stochastic differential equations on a Riemann manifold offers an elementary way to construct equivariant representations of finite-dimensional approximations to the path measure of a diffusion. The key ingredient is the use of the exponential map to describe increments of the diffusion.

Formal Verification of Continuous-Variable Quantum Programs

We provide a formal framework for Continuous-Variable Quantum Computing (CQC). While CQC is supported by photonic quantum hardware, we are not aware of a formal semantics for continuous-variable quantum programs nor of a unary Hoare logic for their verification. There are several technical obstacles to extending to CQC any of the formal frameworks available for Discrete-Vari...

Spatial nonlocality imaging via metasurface

Bell nonlocality is both a defining signature of entanglement and a key quantum information resource. However, visualizing and certifying nonlocal correlations across a spatially multimode photonic field remains challenging due to the rapidly growing measurement cost of spatially resolved projective tests. To address this issue, we build a spatial nonlocality imaging scheme...

Hardware Robustness of Sample-Based Quantum Diagonalization

Sample-based Quantum Diagonalization (SQD) is a hybrid quantum-classical method that replaces variational optimization with a self-consistent recovery loop over QPU samples. Although SQD is considered robust to noisy samples and imperfect classical inputs, its robustness across practical deployment choices has not been systematically analyzed. As a result, shot budgets, qubi...

CutBackdoor: A Circuit Cut Triggered Backdoor Attack on Variational Quantum Algorithms

Variational Quantum Algorithms (VQAs) are a leading paradigm for near-term quantum computing, combining parameterized quantum circuits with classical optimization across quantum chemistry, combinatorial optimization, and quantum machine learning. Since real-world VQA deployments routinely require circuits that exceed available hardware capacity, quantum circuit cutting has b...

Entanglement geometry separates circuit cutting, classical hardness, and trainability

Circuit cutting promises to scale quantum computations beyond current hardware, but variational quantum advantage also requires low cutting overhead, classical hardness, and trainability. We show that these properties are strongly constrained by entanglement geometry. Matrix product state (MPS) and tree tensor network (TTN) circuits with constant seam bond dimension can be c...

Stochastic Pauli-path simulator for large-scale quantum optimization

Pauli-based simulators offer a promising route to large-scale classical simulation of quantum circuits in the low-magic regime. Yet their applicability remains largely limited to forward simulation, making them inadequate for optimization-driven quantum tasks such as variational state preparation and parameter initialization. Existing approaches either lack native support fo...

Light-Cone Scaling of In-Circuit Noise in Randomized Measurements

Randomized measurements provide an efficient way to extract physical properties of an unknown quantum state from limited data. On near-term hardware, gate and readout errors bias the reconstructed observables. Here we develop a microscopic description of this bias for locally scrambled shallow circuits. Independent local twirling reduces local implementation noise to stochas...

Image Classification on IBM Quantum Computers

Quantum machine learning on real noisy intermediate-scale quantum (NISQ) hardware has remained largely confined to binary or few-class tasks, limited by the cost of on-hardware training and the underuse of large devices at inference. We present a unified framework that classifies ten-class MNIST end-to-end on a $127$-qubit IBM Eagle processor, with three central contribution...

Lie-Group Mode Connectivity in Quantum Machine Learning from a Dynamical Lie Algebra Perspective

Mode connectivity has been widely studied in classical machine learning as a geometric property of low-loss regions in parameter space. In quantum machine learning (QML), however, the physically relevant object is not the parameter vector itself but the unitary transformation implemented by a parameterized quantum circuit. In this study, we formulate mode connectivity on the...

Neural Gauge-P Representation for Open Quantum Dynamics of Interacting Bosons

Simulating the nonequilibrium dynamics of interacting open quantum systems remains challenging beyond small system sizes. Quantum phase-space representations provide a scalable approach, but their useful simulation time can be limited by broad distribution tails and the associated boundary terms. We introduce the neural gauge-P representation for open bosonic systems, in w...

Foundry CMOS platform for multimodal quantum materials characterization

Quantum materials experiments increasingly rely on microwave, electrical, thermal, optical, and structural probes, but these capabilities are typically assembled from custom hardware that limits reproducibility and scalability. Here we show that a commercial 65-nm CMOS process can be repurposed as a passive, foundry-manufacturable characterization platform by functionally pa...

IonQ, QuantumBasel Study Suggests Hybrid AI Workloads Could Gain Energy Advantages From Quantum Hardware as Systems Scale

Israel Innovation Authority Launches NIS 100 Million National Quantum Computing R&D Infrastructure

Quantum Computing Inc. Expands Equity Plan After Shareholders Increase Authorized Stock to 450 Million Shares

Non-Abelian Gauge Field Mechanics

Non-Abelian gauge fields play a key role in describing the behavior of particles whose motion is coupled to internal degrees of freedom, such as their spin. Here, we experimentally realize a tuneable non-Abelian gauge field in an active mechanical lattice by using pairs of oscillators to encode a local pseudo-spin for each site, with inter-site spin-dependent couplings engin...

Semi-fractality and localization on a chiral Cayley tree

We study a quantum particle hopping on an infinite Cayley tree with nearest-neighbor hopping amplitudes drawn from a distribution singular as |t|^(-a) near weak links and no on-site disorder. Because the graph is bipartite, the model has chiral symmetry, which strongly affects the statistics of eigenstates at the center of the spectrum. Using population dynamics to solve t...

Exponential Reduction of Mesh Dependence in Quantum Estimation of Parabolic PDE Observables

Can a quantum PDE algorithm avoid the polynomial cost of resolving a fine spatial mesh? For standard fixed-order discretizations, direct classical methods require work polynomial in h^(-1), or equivalently in the number of spatial degrees of freedom N_h=Θ(h^(-d)). Direct quantum implementations of a parabolic semigroup still have coherent complexity ...

Topology of the Set of Entangled State

We investigate the topology of the set E of entangled bipartite density operators acting on C^(n_1)⊗C^(n_2). We start by showing that E is path-connected, and even simply connected except in the two-qubit case. In this exceptional case E turns out to be homotopy equivalent to the set of maximally entangled states, which...

New bound on S_1×S_2-setting Bell locality of a nonseparable Werner state

In many quantum applications it is important to know whether or not a Bell nonlocal two-qudit state exhibits its nonlocality under correlation scenarios with some given numbers S_1,S_2≥1 of generalized quantum measurements at two sites. In the present article, we find analytically a new general condition sufficient for a nonseparable Werner state with a dimension $d...

Universal Dynamic Scaling of 2D Quantum Ising Transition on the Fuzzy Sphere

We revisit the problem of \textit{real-time} quantum dynamics of the paradigmatic two dimensional transverse-field Ising model using the recently developed fuzzy sphere regularization scheme. By linearly ramping the transverse field from the paramagnetic phase to criticality, we study the finite-time scaling behavior of the squared order parameter ⟨m_z^2 ⟩, th...

Strong Quantum Mpemba Effect from Exact Slow-Mode Selection in Constrained Rydberg Chains

Can a many-body state relax faster because it is blind to the slowest decay channel? We show that this mechanism gives rise to a robust strong quantum Mpemba effect in locally dephased constrained Rydberg chains. The key observation is that, for constrained single-spin-flip Hamiltonians, local dephasing turns the Hamiltonian itself into an exact left Liouvillian slow mode, $...

Scanless quantum Fourier-transform mid-infrared spectroscopy for rapid high-sensitivity hyperspectral mapping

Fourier-transform infrared (FTIR) spectroscopy is a well-established technique for qualitative and quantitative chemical analysis. Classical FTIR systems rely, however, on direct mid-infrared (mid-IR) scan-based time-domain measurements of coherence functions; thus, the signal-to-noise ratio and measurement speed are constrained by design. In this paper, we demonstrate a sca...

Noise structuring in fixed-depth Trotter simulation: stationary channels and observable-level depolarization

We analyze fixed-depth Trotter simulation as a method for structuring hardware noise in digital many-body dynamics. The number of layers is chosen using the largest endpoint time and is then kept fixed throughout the time scan, making the total noise dose approximately independent of the endpoint time. For local stochastic faults, we show that, once propagated faults lose me...

Sensing relativistic quantum fields with minimally perturbing local measurements

We develop a framework for minimally perturbing local measurements in relativistic quantum field theory, with the aim to sense local properties of the field in a non-destructive manner. The field properties are sensed by weakly coupled pointers and encapsulated in conditional expectation values dependent on a postselection of the field state. Our operational protocol uses ca...

How the Quantum Sorites Phenomenon Strengthens the Bell Argument and How a Random-Matrix Collapse Dynamics Answers It

Bell proved that no theory of pre-existing local values can reproduce the predictions of quantum mechanics, but his proof leaves the culprit ambiguous: one may reject either of two independence conditions, Outcome Independence or Parameter Independence, and most commentators have found Outcome Independence the safer sacrifice. The first part of this paper presents, in a form...

High-frequency dual-channel lock-in detection via rapidly oscillating driving

Here we propose a general protocol for dual-channel lock-in detection of high-frequency ac signals. We find that the effect of a high-frequency target signal can be modulated through the application of rapidly oscillating driving fields. Based on this mechanism, we develop a quantum dual-channel lock-in detection protocol for high-frequency signals, which not only extends th...

Geometry-Resolved Projection of RF Imbalance to Ion Micromotion in a Same-Phase Dual-RF Blade Trap

Common-mode metrics of a high-Q helical resonator do not determine the residual ion-side field in a dual-electrode drive. We combine a two-node differential RF model with single-electrode finite-element bases to obtain a computation-only, geometry-resolved projection for a same-phase blade trap. For a 3.5 pF external load per branch, the model gives a total effective branc...

Depth Determination of Individual Shallow NV-Centers via Spin-Lock NMR

Quantitative quantum sensing with shallow electron spins, such as those hosted by nitrogen-vacancy (NV) centers in diamond, requires accurate knowledge of the spin's depth below the host material's surface. A widely used approach infers this depth from the 1H nuclear magnetic resonance (NMR) signal of immersion oil on the diamond surface that can be detected using dynamical...

Quantum Key Distribution Beyond Stationary Channels

Quantum key distribution (QKD) over non-stationary channels, such as satellite links, is characterized by short, high-loss, and strongly fluctuating transmission windows that produce sparse detection events. In many QKD protocols, these data must be analyzed using non-IID statistical inequalities, yet existing methods either become loose for small sample sizes or heavily rel...

Variance-Reduced Trajectory Unravelings for GPU Noisy Quantum-Circuit Simulation: Characterization and a Qiskit-Aer Integration Gap

Monte-Carlo trajectory (quantum-jump) methods are the practical route to simulating noisy quantum circuits once the exact density-matrix method is precluded by its 4^n memory cost. Their bottleneck is estimator variance: resolving one expectation value can demand thousands of trajectories. Recent tensor-network work shows that \emph{variance-reduced unravelings} -- project...

Active Optical Frequency Measurements with Superradiance Prolonged by a Modulated Magnetic Field

Superradiant emission from long-lived excited states of an atomic ensemble confined in an optical cavity constitutes a practical source of light with narrow linewidth. In the pulsed regime, however, superradiance implies rapid emission and a broadening of the spectrum. Recent experiments have demonstrated constructive and destructive interference of superradiant emission by...

Fully-connected three-mode squeezed vacuum: Gaussian entanglement, steering, and collective photon subtraction

We investigate a fully-connected three-mode squeezed vacuum (FC-C3MSV) state, where all three modes are pairwise coupled through nonlinear interactions in a triangle (K_3) topology. Using the integration-within-ordered-product technique, we derive the normal product form of the squeezing operator and obtain the covariance matrix directly from the Bogoliubov transformation....

Grounded verification of chemical and materials reasoning: detection is the bottleneck

Large language models confabulate chemical objects (molecular formulas, space groups, formation energies) in fluent reasoning traces, concentrated on long-tail entities where confidence is least trustworthy. Deterministic, database-grounded verification can catch and repair such errors without the coverage cost of blanket retrieval; the binding constraint, we find, is detect...

The History of Hilbert-Space Formulations of Classical Physics

Hilbert-space techniques are widely used not only for quantum theory, but also for classical physics. Two important examples are the Koopman-von Neumann (KvN) formulation and the method of ``classical'' wave functions. As this paper explains, these two approaches are conceptually distinct. In particular, the method of classical wave functions was not due to Bernard Koopman a...

Broadband Polarization Compensation with Link Segment Reconstruction for Quantum Optical Links

Polarization-encoded quantum communication requires compensation of polarization transformations induced by the optical links. If the compensator is embedded between two channel segments, the transformations before and after the compensator must be treated separately. Moreover, standard three-wave-plate polarization controllers can become non-universal when their retardances...

Colored Δ_T noise probes the topological character of edge modes

We investigate colored Δ_T noise, i.e., finite-frequency Δ_T noise, as a probe of edge-mode (EM) transport in quantum Hall and quantum spin Hall systems. Colored Δ_T noise probes finite-frequency nonequilibrium current fluctuations and dynamical transport properties that are often obscured in DC measurements of conductance and noise. Since Δ_T noise is driven solely...

Coexistence of long- and quasi-long range spatial order in 1D quantum quasicrystals

Quasicrystals exhibit long-range positional order without periodicity, arising from multiple incommensurate wave vectors. In self-assembled quasicrystals, the spontaneous breaking of translational invariance gives rise to two Goldstone modes-phonons and phasons-associated with two competing wave vectors. Here, we demonstrate a unique scenario exclusive to quasicrystals: a me...

Scaling law for optimal excitation storage and superradiant release in waveguide QED systems

Driven-dissipative quantum emitters provide a powerful platform for controllable excitation storage and release, with promising applications in quantum batteries and quantum storage. Yet, transient excitation transfer in collective many-body systems is often obscured by the intricate interplay among coherent driving, dissipation, and correlation dynamics. Here, we uncover a...

CQE-led Bloch Quantum Tech Hub Raises $55 Million

Interlune Develops Cryogenic Technology to Expand Helium-3 Supply for Quantum Computing

Maybell Quantum to Establish New Mexico Operations as part of New Mexico’s $450 Million Quantum Initiative

BTQ Technologies and TIDAL PWR Develop Framework for Quantum-Ready Data Centers

DOE Advances Domestic Silicon and Germanium Isotope Supply Chains For Quantum Information Science