June 25, 2026

Simulating Universal Quantum Gate Sets on Photonic OAM Qubits: Single-Qubit and Multi-Qubit Operations via Spatial Light Modulator Phase Holography

Spatial light modulators (SLMs) have emerged as reconfigurable platforms for photonic quantum information processing, offering software-defined control over the orbital angular momentum (OAM) of light encoded in Laguerre-Gaussian (LG) beams. This paper presents a comprehensive simulation and hardware-grounded fidelity analysis of quantum gate operations implemented on the HO...

Tensor network characterization and mitigation of readout errors

Readout errors are a major bottleneck to extracting reliable information from near-term quantum processors, especially when spatial correlations are non-negligible. We present a unified tensor-network framework that models the readout process as a matrix product operator (MPO), enabling efficient characterization and mitigation beyond uncorrelated approximations. The MPO mod...

Evolving Quantum Error-Correcting Encodings for Molecular Simulation

Useful quantum algorithms require many coupled discrete design choices. We study LLM-driven evolutionary program synthesis -- a language model edits a program, an external verifier scores the result, and high-scoring programs are retained and re-mutated -- as a tool for quantum-computing research. As a case study, we apply this loop to the Generalized Superfast Encoding (GSE...

Collective rotational cat states of molecules in microwave cavities

We show theoretically that an ensemble of polar molecules coupled to a microwave cavity supports hybrid rotational-photonic cat states. The cavity couples to a symmetric rotor in the bright manifold of N molecules with √N-enhancement. In the dispersive limit of the collective strong coupling regime, virtual multilevel transitions induce an effective Kerr nonlineari...

Benchmarking Dark Matter Search using a Parity-Check Protocol with Machine-Learning Optimized Pulses

We report on an improved microwave detection protocol for dark matter candidates such as the axion and the dark photon. We employ a superconducting transmon qubit dispersively coupled to a double-cavity system, enabling quantum non-demolition measurements of the photon occupation in a relatively short-lived storage cavity. To reduce the experimental cycle time and enhance se...

Anomalous topological superradiant phases

We present a novel set of light-matter topology realized by implementing a finite-component quantum Rabi array with a photonic analog of the Su-Schrieffer-Heeger (SSH) configuration. We demonstrate how complex light-matter couplings with species-dependent phases lead to the closure of superradiance-induced band gap in a manner that differs from that in the SSH model. We unco...

Preparing two-mode magnonic Schrödinger cat states in a cavity-magnon-qubit system

The cavity-magnon-qubit system has recently been demonstrated as a new platform for preparing macroscopic quantum states in magnonic systems. Here, we propose to prepare a two-mode magnonic cat state, which is also a non-Gaussian entangled state, based on this practical system involving two yttrium-iron-garnet (YIG) spheres and a superconducting qubit coupled to a common mic...

Routing Codes: High-Rate Quantum LDPC Codes with Short, Parallel Non-Local Connectivity

Quantum low-density parity-check (qLDPC) codes are promising candidates for realizing large-scale fault-tolerant quantum computing. Although many codes with favorable theoretical parameters have been developed, their practical adoption must take hardware implementability into account. For mainstream quantum platforms such as superconductors and neutral atoms, the connectivit...

Finite-Shot Sensitivity for Moment Estimation in Quantum Metrology

The quantum Cramér-Rao bound can be saturated only asymptotically and does not specify how many measurements are needed for a concrete estimator to approach it. We develop a finite-measurement theory for method-of-moments estimation, where the parameter is inferred from the sample mean of a calibrating observable rather than from the full likelihood. For general quantum stat...

Two-dimensional Hyperbolic RNN Neural Quantum State

In the first part of this work, we construct the first type of two-dimensional (2D) hyperbolic neural quantum state (NQS) in the form of the Lorentz 2DRNN (Recurrent Neural Network) and benchmark its performance against the Euclidean 2DRNN in the paradigmatic N×N 2D Transverse Field Ising Model (2DTFIM) setting with different lattice sizes up to N=12 and at differe...

Controlling radiative dynamics of a giant Λ-type atom via interference induced by the vacuum of a waveguide

We investigate the dynamics of a Λ-type giant atom (GA) whose both transition coupled to the guided modes of a one-dimensional (1D) waveguide at two spatially separated points with the GA initially excited and the electromagnetic (EM) modes of waveguide in vacuum. The spontaneous emission properties of this GA is investigated by solving the delay-differential equation for...

Hodge Spectral Surrogates for Topology-Constrained Optimization

Topological information is widely used in data analysis, network design, and machine learning, and topological constraints naturally arise when optimizing or generating objects with prescribed homological structure. However, directly controlling Betti numbers and persistent homology is difficult because they are discrete and combinatorial. We propose a differentiable framewo...

AQSolotl and QuantrolOx Partner to Automate Quantum System Calibration

From Rubble Simulation to Active Magnetic Mapping: Quantum Sensing for Disaster Response

Locating survivors of building collapses within the first 72 hours is a critical challenge in disaster response, and existing sensing modalities provide only partial information about the structure beneath the rubble. This paper proposes drone-based quantum magnetometry as a complementary modality and develops a simulation pipeline spanning rubble physics, sensor-array deplo...

Quantum metrology of electric and magnetic dipole moments: ultimate limits and optimal regimes

The characterization of electric and magnetic dipole moments (EDM and MDM) in quantum systems is central to fundamental physics and quantum sensing. While EDM searches provide powerful probes of CP violation within and beyond the Standard Model, precise MDM estimation is crucial for high-precision magnetometry and the development of quantum sensors. In this work, we address...

SPRIND Launches Quantum Sensing Initiative with Dual Innovation Competitions for Germany and Europe

SPRIND (the German Federal Agency for Breakthrough Innovations) has launched the Quantum Sensing Initiative, a long-term strategic framework to accelerate the development, market integration, and scaling of quantum-layer measurement systems within Germany and Europe. Directed by program leaders including Head of Challenges Jano Costard, the initiative addresses early-stag...

QuantWare and Maybell Quantum Partner to Match VIO-40K QPU Architecture with ColdCloud Cryogenics

QuantWare and Maybell Quantum have entered a strategic partnership to ensure hardware compatibility between Maybell's ColdCloud cooling infrastructure and QuantWare's upcoming VIO-40K superconducting quantum processing units (QPUs). By co-designing the processor layout alongside the underlying cryogenic framework, the collaboration aims to optimize the compute-per-watt pe...

QuEra Updates Neutral-Atom Quantum Roadmap with 2028 Fault-Tolerant Launch on Amazon Braket

QuEra Computing Inc. has released its updated product roadmap during a strategic webinar briefing, detailing the transition timelines from Noisy Intermediate-Scale Quantum (NISQ) systems to error-corrected hardware classes. The revised roadmap—anchored upon peer-reviewed academic foundations—outlines a development path optimized for a modular, zoned neutral-atom hardware...

Lawrence Berkeley National Laboratory Outlines Quantum Industry and Computational Infrastructure Partnerships

Faculty Scientist Dan Stamper-Kurn adjusts the optics on a laser experiment. (Credit: Thor Swift/Berkeley Lab) Lawrence Berkeley National Laboratory (Berkeley Lab) has reported the status of its quantum industry collaborations, focusing on the integration of commercial systems and public research infrastructure. Through the National Energy Research Scientific Computing Ce...

STMicroelectronics Launches ST54M Monolithic Mobile Chip with Post-Quantum Cryptography Accelerator

Semiconductor manufacturer STMicroelectronics has introduced the ST54M, a single-die secure mobile processor equipped with a hardware accelerator for Post-Quantum Cryptography (PQC). Designed for smartphones and personal electronics, the chip integrates Near Field Communication (NFC) control circuits, a secure element, and embedded SIM (eSIM) functionality on a single sub...

Classiq and TEA TEK Group Partner to Establish Quantum Computing Hub in Naples

Classiq and technology company TEA TEK Group have announced a strategic partnership to establish a quantum computing hub in Naples, Italy. The facility is configured to operate as a center for quantum computing research, software compilation, and commercial services within Italy and the European Union. By connecting a 128-qubit quantum hardware system with Classiq’s algor...

Higher Berry curvature, second Chern numbers and magnetoelectric coupling in crystalline insulators

We rewrite a lattice model of the four-dimensional Chern insulator as a family of translationally-invariant infinite chains over the three-dimensional Brillouin zone and compute its higher three-form Berry curvature using infinite matrix product states (iMPS). We calculate the topological phase diagram of the associated Dixmier--Douady--Kapustin--Spodyneiko (DDKS) number as...

Fast mixing of all-to-all quantum systems at high temperatures

It is shown that arbitrary quantum k-local Hamiltonians with bounded strength interactions admit a quantum Gibbs sampler [CKG23] with a system-size independent spectral gap, at sufficiently high temperatures. This generalizes the existing quantum fast-mixing results beyond the geometrically-local setting. As a consequence, such systems admit fully-polynomial time quantum a...

Analytic Approach to Quantum Control Using Quantum Signal Processing

Realizing coherent quantum computation requires precise and robust manipulation of quantum systems through quantum control protocols. Most quantum control techniques rely on heuristic methods for designing the driving pulses that steer the system towards a target state. Such methods are often based on brute-force optimization and offer limited understanding of the solution l...

Operational detection of Wigner negativity in arbitrary quantum states from few copies

States with negative Wigner functions form a fundamental class of nonclassical resource underlying quantum advantage. Here we develop a unified framework to detect Wigner negativity of arbitrary states using experimentally accessible moments of the Wigner function that can be estimated from a modest number of state copies. Exploiting constraints satisfied by positive phase-s...

Folds of one curve: the superradiant phase diagram of Dicke modes with interacting matter

We give a thermodynamic-limit account of Dicke models with one cavity mode coupled collectively to interacting matter. Integrating out the cavity yields an exact self-consistent functional of the magnetisation m, e(m) = λm^2/2 + e_(rmmat)(λm): a classical penalty on the bare-matter energy e_(rmmat) in the self-consistent field h = λm, with λ= g^2/(2ω_c)...

Many-Body Second Order Green's Function Theory for Ab Initio Molecular Quantum Electrodynamics

In this work, we develop two many-body quantum electrodynamic methods to calculate the ground-state energies of strongly coupled light-matter molecular systems. Specifically, we extend the second-order many-body Green's function theory (GF2) for electronic systems to incorporate electron-boson couplings. We employ two ansätze to treat the bosonic part of the system, namely t...

Estimating Fidelity to a Reference Quantum State

We consider the problem of estimating the fidelity of an unknown quantum state to a known reference state to within additive error ε. We show that the sample complexity is O(r^2/ε^2) with optimal ε-dependence when the reference state is of rank r, improving the previous best O(r^2log^2(1/ε)/ε^4) due to Utsumi, Naka...

From spectral structure to sensing limits in quantum thermometry

The precision of a quantum thermometer is fundamentally constrained by the spectral structure of the probe itself, and a systematic mapping between the configurations of energy levels and thermometric performance provides relevant information to design optimized devices. In this work, we establish such a mapping by analyzing a broad class of quantum systems, ranging from fin...

Klein--Gordon Dynamics from Intrinsic Phase Periodicity

This work develops a phase-based formulation of relativistic wave dynamics, demonstrating that the Klein--Gordon equation emerges naturally from the foundational assumption of intrinsic phase periodicity in material fields. Mapping the phase directly onto the classical action, we postulate that localized excitations possess an invariant rest-frame oscillation governed by a p...

Resonant false vacuum decay in two dimensions on a 4000-qubit quantum annealer

From cosmology to quantum matter, metastable states often decay through the nucleation and growth of competing domains, with false vacuum decay providing the paradigmatic example of this process. Here we demonstrate a distinct regime in which domain growth outpaces nucleation by orders of magnitude and is controlled by local resonance conditions. Using a programmable quantum...

Nonlinear Dynamics of Coherent Parametric Amplification in Multipartite two-level System under Intrinsic Decoherence

In this work, we study the dynamics of global quantum discord and quantum Fisher information in a multipartite system of two-level atoms interacting with a coherent field. The model includes parametric amplification, Kerr-type nonlinearity, and intrinsic decoherence to examine how these effects control quantum correlations and parameter-estimation sensitivity. The results sh...

A Candidate Framework for Free-Space Quantum Key Distribution based on Geometrical-Configuration Modulation

This paper proposes a candidate framework for free-space quantum key distribution (QKD) based on geometrical-configuration modulation (GM). In the minimal implementation considered here, Alice coherently splits a single photon emitted from one source into two spatial output modes with a tunable separation, and uses the source separation R as the GM variable that defines th...

A Short Note on the Generators of Controlled Quantum Gates

We present the analytical generators for arbitrary multi-qubit controlled gates. Closed forms for the generating Hamiltonians are given for gates with both multiple control and target qubits, as well as for arbitrary control conditions. This allows us to go beyond gate-based simulations of quantum circuits and incorporate decoherence and other noise in simulations of quantum...

Sp(2N, R) interferometry in multi-mode Gaussian bosonic systems for optimal metrology and quantum control

Multi-mode interferometers for bosons in Gaussian states are important systems for quantum metrology with precision beyond the standard quantum limit and for bosonic quantum computing. However, there is a lack of theoretical foundation for generic N-mode Gaussian interferometry. In this work, we study quantum metrology and quantum control in multi-mode bosonic systems with...

Radial Schmidt mode detector of entangled photons

High-dimensional spatially entangled two-photon state generated by spontaneous parametric down-conversion process (SPDC) has become a promising resource for several quantum information science applications. For harnessing high-dimensional entanglement advantages, detection capability in the Schmidt basis is a necessity. Spatial entanglement has been explored in several modal...

Quantum steering in networks: Measurement-device-independent detection, continuous variables, and practical Gaussian schemes

We consider quantum steering certification in multipartite networks, with a focus on minimal trust scenarios: all-except-one parties are untrusted and treated device-independently. We show that it is always possible to lift steering certification to the measurement-device-independent regime, in which even the (last) trusted party can treat their local hardware as a black-box...

Exact Leg-Cut Influence Functional and Emergence of Gaussian Entanglement Theory in a Statistical-Dressing Ladder Model

The emergence of Gaussian effective field theories in low-dimensional quantum systems is traditionally understood through top-down frameworks such as bosonization and Luttinger-liquid theory. However, these approaches typically focus on the long-wavelength degrees of freedom in ways that do not directly track how non-Gaussian lattice-scale correlations are progressively disc...

Quantum Detectability in Invisibility Cloaks

Classical invisibility cloaks are designed to suppress selected scattering signatures and thereby make an object appear absent to external electromagnetic probes. However, the suppression of a classical scattering observable does not, by itself, establish that all information about the concealed object has been removed from the detected quantum state of light. Here we formul...

Long-lasting Topological Entanglement in a Monitored Rashba Nanowire

We study the topological properties of a monitored Rashba chain along quantum-jump trajectories, investigating the persistence of the initial topological value of the disconnected entanglement entropy (DEE). We find that the DEE persists in its topological value for a time linear in the system size, even if the dissipation acts on the boundary and affects the topological Maj...

Spin-Momentum Impedance and Filtering by a Spin-Coupled Absorbing Boundary Condition

Absorbing boundaries are often treated as scalar sinks. Here we show that a spin-coupled absorbing boundary for a Pauli particle acts instead as a spin--momentum impedance. Its tangential boundary symbol has two branches, iκ±|ξ|, coupling normal absorption to in-plane momentum. In a harmonic guide, the transverse ground state samples |ξ|~ℓ_...

Towards Robust Optimal Measurements Against Noise in Quantum Metrology

Quantum parameter estimation utilizes quantum mechanical effects to attain higher measurement precision than classical schemes. In practical implementations, however, noise is inevitably present during the measurement process, causing a decrease in precision. Quantifying the impact of noise on different measurements is of considerable significance. Here, we experimentally in...

The Cost of Removing Tunability in Quantum Data Re-Uploading

Fixed encoding data re-uploading quantum circuits provide a striking example of universality emerging from a highly constrained architecture. However, universality alone is insufficient for assessing the theoretical and practical value of fixed and tunable upload circuits. The resource cost of removing tunability remains poorly understood. In this work, we establish quantita...

A phase-space approach for performing continuous-variable quantum teleportation with a non-Gaussian resource

We present a comprehensive phase-space analysis of continuous-variable quantum teleportation employing a photon-subtracted two-mode squeezed Fock state (PS-TMSFS) as an entangled resource. We investigate the usefulness of PS-TMSFS within the Braunstein-Kimble teleportation protocol. We explain the generation scheme for the resource state and derive the analytical expression...

Weak decay of the positronium ion

The positronium ion (Ps^-), a coulombic three-body bound state of two electrons and a positron, predominantly decays via electron-positron annihilation into electromagnetic final states. While its radiative decay channels have been extensively studied, much less attention has been given to weak processes in this system. In this work, we investigate the rare decay...

Spin-imbalanced fermion on a dynamic lattice

We investigate the magnetic order of a one-dimensional spin-1/2 fermion dynamical lattice, where itinerant fermions are coupled to bond-centered localized spins via an Ising-like spin dependent hopping. The model provides an anisotropic dynamical extension of conventional spin-1/2 fermion systems, in which the motion of itinerant fermions is directly modulated by the configu...

Quantum tomography of free electrons

Determining the quantum state of a given quantum-mechanical system is a fundamental task in physics. Quantum-state tomography has been pivotal for establishing quantum optics [1-4] and for revealing the properties of bound charges in materials [5-7]. An emerging other object for studying and utilizing quantum effects are free electrons, elementary particles that are central...

Wide-field NV magnetometry under simultaneous high-pressure and high-temperature conditions

We demonstrate wide-field optically detected magnetic resonance (ODMR) under simultaneous high-pressure and high-temperature conditions using nitrogen-vacancy (NV) centers. Although NV-center magnetometry has been widely used for spatially resolved magnetic-field imaging, its application to extreme environments combining pressure and temperature remains challenging. In this...

A Unified Josephson Dynamics Perspective for Single-Cavity BECs: From Self-Trapping to Dynamical Phase Transitions

We investigate a two-component Bose-Einstein condensate (BEC) strongly coupled to a single optical cavity, effectively described by a mean-field Dicke model supplemented with interatomic nonlinearities. Here, we propose a unified theoretical framework demonstrating that macroscopic quantum self-trapping (MQST) natively emerges between two internal atomic energy levels within...

Rapid and robust laser-frequency auto-locking using Bayesian-optimization and discrete-wavelet-transformation algorithms

Rapid and robust laser-frequency auto-locking is essential for the field deployment of quantum communications, quantum computing, and precision-measurement technologies; however, achieving this remains a considerable challenge. Here, we propose and demonstrate an auto-locking scheme employing Bayesian optimization and discrete biorthogonal wavelet transformation. First, the...

Quantum conditional mutual information and channel capacity

Information measures acquire operational meaning through coding theorems. The quantum conditional mutual information (QCMI) is nonnegative due to strong subadditivity, yet a direct connection with channel coding has remained elusive. In this work, we propose a quantum communication task-conditional quantum communication-that fills this gap. We show that the optimal rate for...

A Mean-Field Lindblad Master Equation Framework for Interaction-Driven Decoherence in Solid-State Qubit Ensembles

Multi-qubit systems are essential for scalable quantum technologies, but their performance is often limited by decoherence from qubit--qubit interactions and environmental noise. Although environmental decoherence in single-qubit systems and gate fidelity in multi-qubit systems have been widely studied, a predictive framework connecting qubit interactions, concentration, spa...

Closed Quantum Boltzmann Bridges: Coherent Revivals, Hidden Microstates, and the Emergence of Classical Two-Time Entropy Conditioning

The classical Boltzmann Bridge describes entropy histories conditioned on both an initial low-entropy macrostate and a later macrostate. Unlike the usual past-only formulation of the thermodynamic arrow, this two-time conditioning can produce entropy profiles that rise above the final entropy and then decrease toward the imposed endpoint. In this work, we formulate closed qu...

Halo-Independent Quantum Sensor Probes of Low-Velocity Dark Matter

We present a halo-independent framework for sub-GeV dark matter (DM) direct detection using quantum sensors with sub-eV energy thresholds. Such detectors enable access to low DM velocities and may be sensitive to departures from the Standard Halo Model that are challenging to probe with conventional direct DM detection experiments. The method expresses the DM scattering even...

Self-testing Quantum Supermaps

By certifying quantum operations from measurement statistics directly, without any assumption on the internal workings of the devices involved, self-testing enables a uniquely reliable identification of quantum objects. While such device-independent characterization has been shown to be possible for states, measurements and channels, it has so far not been extended to quantu...

NSF Selects Five Additional Teams in National Quantum Virtual Laboratory Design Competition

The U.S. National Science Foundation (NSF) has selected five additional research teams to participate in the design phase of the National Quantum Virtual Laboratory (NQVL). Backed by a collective investment of $20 million, the expansion brings the program's total portfolio to nine projects following the initial cohort selection. Each team will receive $4 million over [......

Classiq and Hatch Validate Hybrid Quantum-Classical Chemistry Pipeline on AWS Infrastructure

Software developer Classiq and innovation center Hatch have completed a computational chemistry proof-of-concept (PoC) to estimate molecular binding energy via Amazon Web Services (AWS) and Amazon Braket. Executed through Hatch’s Dimension X open innovation challenge for Singapore’s Home Team and aligned with Singapore’s National Quantum Strategy, the project establishes...

Economist Columnists Say U.S. Quantum Investments Show Promise — But Need Clearer Rules

The Conversation: A New Quantum Computer Sets a High Watermark For Accuracy – Are We on The Verge of a Big Breakthrough?

NSF Selects Five New Teams for National Quantum Virtual Laboratory