Quantum Computing
Quantum Computing news — Monday 19 October 2026
146 stories from 3 sources, every one in English. Each links to its publisher.
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Chinese Startup FlipFlop Tuoyuan Emerges with Major VC Backing for 100-Logical-Qubit Neutral-Atom Systems
Quantum Computing Report
FlipFlop Tuoyuan, a Chinese quantum hardware startup, has secured over $14 million in early-stage funding to develop neutral-atom quantum processing units. Founded in July 2026 by Dr. Qiao Mu, the company aims to build a 100-logical-qubit…
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UK Government and UKRI Unveil £78M ($103.8M USD) Quantum Commercialization, Networking, and Skills Package
Quantum Computing Report
The UK government and UK Research and Innovation (UKRI) have announced a £78 million (approximately $103.8 million USD) funding package to advance quantum sensing, networking, and workforce development. This initiative, part of the…
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Podcast with Joel Van Dyk, CTO/CISO and Co-Founder of Done. Quantum Security Limited
Quantum Computing Report
Podcast with Joel Van Dyk, a physicist turned Wall Street cybersecurity veteran, about the quantum threat to cryptography and what organizations should be doing right now to prepare. The post Podcast with Joel Van Dyk, CTO/CISO and…
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NVIDIA and Jülich Run 104-Qubit Magic State Cultivation Simulation on JUPITER Supercomputer
Quantum Computing Report
NVIDIA and Jülich Supercomputing Centre simulated a 104-qubit fault-tolerant quantum computing experiment on the JUPITER supercomputer, Europe's first exascale system. This simulation, detailed in an NVIDIA technical report, validated a…
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Xanadu Secures Up to $10 Million in Additional DARPA Funding Under QBI Program
Quantum Computing Report
Xanadu, a photonic quantum computing company, has secured up to $10 million in additional DARPA funding through the Quantum Benchmarking Initiative (QBI). This one-year contract extension will support Xanadu's hardware and software…
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NVIDIA Runs Simulation of Fault-Tolerant Quantum Computing at Jülich Supercomputing Centre
The Quantum Insider
Insider Brief NVIDIA simulated a 104-qubit fault-tolerant quantum processor on Europe’s JUPITER supercomputer to evaluate magic-state cultivation under realistic hardware noise. The approach studied could reduce the qubits needed to…
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Quantinuum Demonstrates 99.9995% Logical Memory Fidelity on Helios Trapped-Ion Processor
Quantum Computing Report
Quantinuum has demonstrated a 99.9995% logical memory fidelity on its Helios trapped-ion quantum computer, achieving a logical error rate of 5 × 10-6 per syndrome-extraction round on a distance-7 code. This performance shows exponential…
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Quantinuum Reports a 10x Reduction in Logical Error Rate on Helios
The Quantum Insider
Insider Brief Quantinuum reported 99.9995% logical fidelity on its Helios quantum computer using a color code, equivalent to five errors per million operations and a tenfold reduction from its previous result. Logical errors decreased…
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China’s Tuoyuan Targets Neutral-Atom Quantum Computing
The Quantum Insider
Insider Brief Chinese startup Tuoyuan, led by quantum researcher Mu Qiao, is pursuing neutral-atom quantum computing with a reported development target of 100 logical qubits. QbitAI reported that the company raised hundreds of millions of…
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Advance Could Lead to Bigger, More Reliable Quantum Computers, University of Edinburgh Scientists Say
The Quantum Insider
Insider Brief Researchers developed an algorithm that allows standard computers to simulate photonic quantum devices using about 5% of the computing power previously required, according to the team. In tests involving Gaussian boson…
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RIKEN Team Improves Parallel Control of Silicon Spin Qubits
The Quantum Insider
Insider Brief RIKEN researchers demonstrated high-accuracy parallel control of silicon spin qubits using a shared microwave line and a calibration method that reduces control errors. Pairwise phase calibrations helped maintain gate…
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UKRI Backs UK Quantum Businesses With Share of £50 Million
The Quantum Insider
Insider Brief UK Research and Innovation (UKRI) has announced £50 million for UK quantum technology projects, alongside separate funding for quantum networking infrastructure and workforce training. The funded projects include MoniRail ‘s…
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Learning angles for quantum approximate optimization
arXiv quant-ph
arXiv:2610.23296v1 Announce Type: new Abstract: The Quantum Approximate Optimization Algorithm (QAOA) and its variants are leading algorithms to help solve challenging combinatorial optimization problems. QAOA maps these problems to Ising…
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Metric and Dispersive Dynamics of Phase Perturbations in Bohmian Quantum Mechanics
arXiv quant-ph
arXiv:2610.22737v1 Announce Type: new Abstract: By linearizing the hydrodynamic equations associated with the Madelung transformation in the context of Bohmian dynamics, we derive an effective metric for the phase perturbation around a…
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Multi-Time States in Quantum and Operational Probabilistic Theories: An Axiomatic Framework
arXiv quant-ph
arXiv:2610.22489v1 Announce Type: new Abstract: Quantum states over time were introduced, in part, to extend Bayesian probability to quantum theory and have since found applications across diverse areas, ranging from quantum causality and…
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Trapping of nanofabricated SiO$_2$ high-aspect-ratio discs in an optical lattice
arXiv quant-ph
arXiv:2610.22614v1 Announce Type: cross Abstract: We describe the nanofabrication and loading of lithographically patterned, high aspect ratio $10$ $\mu$m diameter silicon dioxide discs with thickness of $400$ nm into an optical standing…
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Scaling of entanglement with distance between subsystems: detection of phase transitions in the $t'$-$\pi$-flux model
arXiv quant-ph
arXiv:2610.23770v1 Announce Type: cross Abstract: The system-size scaling of bipartite entanglement can be used to detect phase transitions. We develop a related approach for strongly correlated electron models where large density matrices…
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Diagrammatic Reasoning with Control as a Constructor, Applications to Quantum Circuits
arXiv quant-ph
arXiv:2508.21756v4 Announce Type: replace Abstract: Control is a fundamental concept in quantum and reversible computational models. It enables the conditional application of a transformation to a system, depending on the state of another…
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The three kinds of three-qubit entanglement
arXiv quant-ph
arXiv:2511.07617v3 Announce Type: replace Abstract: We construct an important missing piece in the entanglement theory of pure three-qubit states, which is a polynomial measure of W-entanglement. This works in parallel to the three-tangle…
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Temporal Interference from Topological Transitions in Monitored Quantum Dynamics
arXiv quant-ph
arXiv:2607.27045v2 Announce Type: replace-cross Abstract: Quantum interference is conventionally associated with the coherent superposition of alternative paths. We uncover a temporal form of interference in repeatedly monitored quantum…
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Quantumness of Entanglement in Schwarzschild de Sitter Spacetime
arXiv quant-ph
arXiv:2610.22761v1 Announce Type: new Abstract: We investigate genuine multipartite entanglement and genuine tripartite nonlocality of a noisy generalized GHZ state in Schwarzschild-de Sitter spacetime. The genuine multipartite concurrence…
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Certifying information flow in multi-agent behaviours
arXiv quant-ph
arXiv:2610.23631v1 Announce Type: new Abstract: We study which input-output behaviours of several agents can be produced by a declared communication schedule, that is, a fixed sequence of senders, recipients, message alphabets, and output…
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Analytic formulae for non-local nonstabiliserness in bipartite systems of qutrits and ququints
arXiv quant-ph
arXiv:2603.09155v2 Announce Type: replace Abstract: We conjecture analytic expressions for the non-local magic of bipartite pure qudit states of prime local dimension. Our construction relies on the Schmidt-aligned state attaining the…
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Quantum instanton theory for metastable collective spin systems
arXiv quant-ph
arXiv:2604.15091v2 Announce Type: replace Abstract: Collective spin systems -- driven-dissipative spin ensembles whose unitary and dissipative processes act uniformly on all spins, allowing their dynamics to be described as a single…
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Resonance crossings and diabolical points for DC electric field quantum sensors
arXiv quant-ph
arXiv:2610.23392v1 Announce Type: new Abstract: Since the 1990s, experiments on double-well heterostructures have highlighted a key phenomenon: applying an external DC electric field induces pronounced wave packet oscillations at specific…
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Quantum Circuits for Variable-Coefficient Vlasov Dynamics via Schr\"odingerisation
arXiv quant-ph
arXiv:2610.23405v1 Announce Type: new Abstract: High-dimensional Vlasov equations present promising use cases for quantum simulation, but their transport coefficients must be implemented coherently in order to preserve a compact quantum…
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Electrostatic Limits on Quantum Spatial Search
arXiv quant-ph
arXiv:2610.23560v1 Announce Type: new Abstract: We prove that a quantum walker cannot search a two-dimensional lattice in Grover's $O(\sqrt N)$ time, resolving the long-standing open question posed by Aaronson and Ambainis in 2003. A…
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Circuit-based characterization of finite-temperature quantum phases and self-correcting quantum memory
arXiv quant-ph
arXiv:2509.15204v3 Announce Type: replace Abstract: Quantum phases at zero temperature can be characterized as equivalence classes under local unitary transformations: two ground states within a gapped phase can be transformed into each…
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ConQUESTA: Topology-Aware Post-Training Structural Pruning of Quantum Neural Networks
arXiv quant-ph
arXiv:2610.23415v1 Announce Type: new Abstract: Deploying quantum neural networks (QNNs) on sparse hardware requires preserving task accuracy while reducing compiler-induced two-qubit gates, SWAPs, and depth. We present ConQUESTA…
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Leveraging verifiable structure in quantum circuits to find more efficient compilations with agentic AI
arXiv quant-ph
arXiv:2610.23832v1 Announce Type: new Abstract: We discuss an effective paradigm of utilizing AI agents to better compile quantum circuits when one can constrain bottleneck subroutines to have some form of classically verifiable structure…
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Floquet-ADAPT-VQE: A Quantum Algorithm to Simulate Non-Equilibrium Physics in Periodically Driven Systems
arXiv quant-ph
arXiv:2503.11613v3 Announce Type: replace Abstract: Periodically driven quantum systems exhibit many fascinating phenomena absent in equilibrium systems, but their simulation is more challenging than that of static systems. Consequently…
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Perspective: Quantum Computing on Magnetic Racetrack
arXiv quant-ph
arXiv:2604.19304v2 Announce Type: replace-cross Abstract: Magnetic domain walls have long been pursued as carriers of classical information for storage and processing. With the ability to create, control, and probe domain walls at the…
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Exponential-SWAP gate between bosonic motional modes of trapped ions
arXiv quant-ph
arXiv:2610.23208v1 Announce Type: new Abstract: The exponential-SWAP (eSWAP) gate generates a coherent superposition of identity and SWAP operations, with continuously tunable amplitudes. We experimentally implement this gate between two…
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Quantum key distribution over a 2 km free-space channel with a high secure key rate
arXiv quant-ph
arXiv:2607.24118v2 Announce Type: replace Abstract: Free-space quantum key distribution (QKD) provides crucial advantages, including mobility and deployment exibility, for securing next-generation communication networks. However…
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Classification of bipartite observables II: NIP observables and the Todorcevic trichotomy
arXiv quant-ph
arXiv:2610.12908v2 Announce Type: replace Abstract: A bipartite observable is stable when its expectation does not depend on which system is idealized first. We show that it is stable exactly when its idealized responses are continuous…
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From Atomistic Impurity Landscapes to Two-Level-System Distributions and Microwave Loss: Hydrogen-Induced Losses in Nb$_2$O$_{5-\delta}$ and Ta$_2$O$_{5-\delta}$
arXiv quant-ph
arXiv:2603.17194v2 Announce Type: replace-cross Abstract: We introduce a first-principles-guided framework for predicting statistical TLS distributions from mobile impurities in disordered materials. Machine-learned interatomic potentials…
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Anticommuting Displacement Operators, Exact Pauli Algebras,and the Singlet State from the Oscillator Vacuum
arXiv quant-ph
arXiv:2610.23264v1 Announce Type: new Abstract: We give an explicit construction of a pair of anticommuting Weyl displacement operators for a harmonic oscillator and use bounded functional calculus to obtain exact dichotomic…
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A Fibre-Integrated SPDC Heralded Single-Photon Source Using Zn-Indiffused PPLN Ridge Waveguides at Telecom Wavelengths
arXiv quant-ph
arXiv:2610.23499v1 Announce Type: new Abstract: We demonstrate a fully fibre-integrated source of broadband polarisation-entangled photon pairs at telecom wavelengths based on a commercially available Zn-indiffused MgO:PPLN ridge waveguide…
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Semiclassical Analysis of Wave Dynamics via Wigner Transforms: Applications to the Quantum Harmonic, Anharmonic, and Dirac Oscillator
arXiv quant-ph
arXiv:2610.22414v1 Announce Type: cross Abstract: In this Master's thesis, we give a pedagogical introduction to the semiclassical analysis of wave dynamics in single-band and multi-band systems. We show how the semiclassical evolutions of…
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Area Theorems for Quantum Error Correction
arXiv quant-ph
arXiv:2610.22710v1 Announce Type: cross Abstract: The extrinsic information transfer (EXIT) and generalized EXIT (GEXIT) area theorems provide fundamental conservation laws that connect the rate of classical codes to the performance of…
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Enhancing Quantum Metrology with High-order Fisher Information and Experiments
arXiv quant-ph
arXiv:2606.27633v2 Announce Type: replace Abstract: Fisher information plays a central role in statistics and quantum metrology, providing the basis for the celebrated Cram\'{e}r-Rao bound. In this work, we introduce a new information…
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Controlled PROP: Theory and Applications to Quantum Circuits
arXiv quant-ph
arXiv:2610.23192v1 Announce Type: new Abstract: Control is a fundamental concept in quantum and reversible computational models. It enables the conditional application of a transformation to a system, depending on the state of another…
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Quantum Sensitivity of $N$-Component Cat States
arXiv quant-ph
arXiv:2610.23398v1 Announce Type: new Abstract: We extend our previous study of squeezed two-component Schr\"odinger cat states to a phase-referenced single-mode family with an arbitrary number $N$ of coherent components and general…
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Exponential clustering of bipartite quantum entanglement at arbitrary temperatures
arXiv quant-ph
arXiv:2108.12209v5 Announce Type: replace Abstract: Macroscopic quantum effects play central roles in the appearance of inexplicable phenomena in low-temperature quantum many-body physics. Such macroscopic quantumness is often evaluated…
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Scalable Tomography of Coherent Noise via Stabilizer-Code Polarization
arXiv quant-ph
arXiv:2610.19779v2 Announce Type: replace Abstract: Coherent errors accumulate linearly rather than diffusively, making them invisible to Pauli-twirl-based char- acterization. It poses a central challenge for quantum error correction, yet…
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A thermally and perturbatively stable classical spin model in two dimensions
arXiv quant-ph
arXiv:2610.22548v1 Announce Type: new Abstract: We show that the 2D classical spin model constructed in arXiv:2605.10943 hosts many metastable states at non-zero temperature which are stable to arbitrary Hamiltonian perturbations…
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Circuit Synthesis for Variational Quantum Algorithms: The Depth of Algebra and Geometry
arXiv quant-ph
arXiv:2610.22689v1 Announce Type: new Abstract: The analysis of Hamiltonian Variational Ans\"atze centers on three fundamental questions: which states are exactly reachable from a given initial state, what native control depth suffices for…
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Quantum-Assisted Unambiguous Discrimination of Pure States with Robustness Bounds
arXiv quant-ph
arXiv:2610.22954v1 Announce Type: new Abstract: We propose a hybrid quantum-classical framework for the unambiguous discrimination of pure states by combining the noisy intermediate-scale quantum semidefinite program solver (NSS) with the…
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Delta-sigma noise shaping for low-resolution quantization in Gaussian-modulated continuous-variable quantum key distribution
arXiv quant-ph
arXiv:2610.23654v1 Announce Type: new Abstract: Low-resolution digital-to-analog conversion can simplify continuous-variable quantum key distribution (CVQKD) transmitters, but coarse quantization increases excess noise and can generate…
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Partially isophase electro-magnetic configurations
arXiv quant-ph
arXiv:2610.23645v1 Announce Type: new Abstract: Separation of variables in Schr\"{o}dinger equation allows an infinite-dimensional family of physically distinct field configurations that are dynamically indistinguishable in one selected…
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Dilaton-Axion Wormhole Partition Function Away from the BPS Endpoint
arXiv quant-ph
arXiv:2610.22429v1 Announce Type: cross Abstract: I determine the leading finite-radius correction to the two-boundary response of a charged axion wormhole near its BPS endpoint. With $\delta=a_*^2$, exact radial matching in a product…
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Chirality-resolved imaging of spin waves with a quantum spin
arXiv quant-ph
arXiv:2610.22867v1 Announce Type: cross Abstract: Spin waves carry their propagation direction in the handedness of their circularly polarized stray field, a property inaccessible to scalar magnetometers. In the Damon-Eshbach surface wave…
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Unconditional Quantum PAC Learning Advantage in the Large Error Regime
arXiv quant-ph
arXiv:2610.23268v1 Announce Type: cross Abstract: We establish an unconditional super-polynomial separation between quantum and classical PAC learning of Boolean functions under the uniform distribution in the large error regime. For every…
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Logarithmic-depth quantum state preparation of polynomials
arXiv quant-ph
arXiv:2603.16527v4 Announce Type: replace Abstract: Quantum state preparation is a central primitive in many quantum algorithms, yet it is generally resource intensive, with efficient constructions known only for structured families of…
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Building codes with transversal CCZ using projective geometry and SAT solvers
arXiv quant-ph
arXiv:2610.09341v2 Announce Type: replace Abstract: We construct CSS codes with three logical qubits whose logical CCZ gate is implemented by transversal physical $T/T^\dagger$ gates and whose distance is at least 3. These codes start with…
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An Instability of the Quantum Markov Length
arXiv quant-ph
arXiv:2610.12929v2 Announce Type: replace Abstract: The Markov length, the length scale governing the exponential decay of conditional mutual information (CMI) in a quantum many-body state, has proven useful for characterizing mixed-state…
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Rate and depth of two-axis twisting by pair exchange under the self-Kerr constraint
arXiv quant-ph
arXiv:2610.15774v2 Announce Type: replace Abstract: In this paper, we study two bosonic modes that exchange pairs of quanta, which realize two-axis twisting exactly: within a sector of fixed particle number the exchange operator is…
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Accurate gap control of 3D-integrated superconducting quantum circuits using asymmetric indium architecture and multi-angle flip-chip bonding
arXiv quant-ph
arXiv:2610.21435v2 Announce Type: replace Abstract: Flip-chip 3D integration is a key enabling technology for overcoming the routing and layout constraints of planar superconducting quantum processors, but it requires accurate and uniform…
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Limits of adaptive two-way linear postprocessing in six-state quantum key distribution
arXiv quant-ph
arXiv:2610.21469v2 Announce Type: replace Abstract: Two-way classical communication improves the noise tolerance of quantum key distribution, but the limits of adaptive parity processing remain unclear. For the six-state protocol with…
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Level statistics of the disordered Haldane-Shastry model with $1/r^\alpha$ interaction
arXiv quant-ph
arXiv:2604.14695v2 Announce Type: replace-cross Abstract: Understanding how the interaction range and various types of disorder affect the level statistics of many-body quantum systems, leading to the emergence of many-body localization…
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Universal Emergence of Bosonic and Fermionic Algebras in a Deterministic Proper-Time Framework
arXiv quant-ph
arXiv:2608.14816v2 Announce Type: replace-cross Abstract: This work develops the deterministic, discrete proper-time framework introduced in our previous work, Eur.\ Phys.\ J.\ C \textbf{86} (2026) 829, in which quantum field theory…
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Exact Gaussian--Hermite closure of the mapping quantum--classical Liouville equation
arXiv quant-ph
arXiv:2610.16864v2 Announce Type: replace-cross Abstract: In the Meyer--Miller--Stock--Thoss mapping representation, the Liouville operator of the quantum--classical Liouville equation contains an excess coupling term in addition to the…
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Programmable Preparation of Topological Entangled States
arXiv quant-ph
arXiv:2610.22738v1 Announce Type: new Abstract: Programmable preparation of entangled quantum states is a central requirement for scalable quantum information processing, quantum networking and photonic quantum computing. Topological…
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Bottlenecks in quantum channels and finite temperature phases of matter
arXiv quant-ph
arXiv:2412.09598v2 Announce Type: replace Abstract: We prove an analog of the "bottleneck theorem," well-known for classical Markov chains, for Markovian quantum channels. In particular, we show that if two regions (subspaces) of Hilbert…
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Learning Midcircuit Measurement Backaction from Three Repeated Measurements
arXiv quant-ph
arXiv:2606.00433v3 Announce Type: replace Abstract: Accurate modeling of midcircuit measurements (MCMs) is essential for dynamic-circuit operations such as syndrome extraction, measurement-based reset, and the separation of…
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Sufficient quantum provenance: retained fields and certified recording precision
arXiv quant-ph
arXiv:2610.09931v3 Announce Type: replace Abstract: Quantum executions sharing a provenance record can produce different output distributions. We ask which execution details to retain, and at what precision, to guarantee agreement within a…
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Combinatorial aspects of holographic quantum secret sharing
arXiv quant-ph
arXiv:2607.16110v2 Announce Type: replace-cross Abstract: We introduce combinatorial holographic quantum secret sharing (CHQSS) for a bulk subregion in AdS$_3$/CFT$_2$ to study how logical information of the bulk subregion is encoded in…
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Geometric inflation of deviations challenges neural quantum states in dynamics of quantum Ising models
arXiv quant-ph
arXiv:2609.07645v2 Announce Type: replace Abstract: Neural quantum states (NQS) have emerged as a powerful framework for simulating non-equilibrium dynamics in strongly correlated quantum systems, offering scalable variational…
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Typical Superpositions are Magical
arXiv quant-ph
arXiv:2610.22476v1 Announce Type: new Abstract: The non-stabilizerness, or "magic", of a quantum state is a common metric for the hardness of simulation on a classical computer, and is often quantified by the stabilizer R\'enyi entropy…
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Exploring Quantum Phase Transitions Beyond Landau Theory on a Quantum Processor
arXiv quant-ph
arXiv:2610.22482v1 Announce Type: new Abstract: Direct continuous quantum phase transitions between phases that break distinct symmetries challenge the conventional Landau-Ginzburg-Wilson paradigm and provide a framework for deconfined…
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From quantum emitters to technological platforms: a perspective on semiconductor quantum dots
arXiv quant-ph
arXiv:2610.23106v1 Announce Type: cross Abstract: Photonic quantum technologies are based on controlled photon states. To generate these, quantum dots have emerged as excellent sources of single and entangled photons. In this Perspective…
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A Quantum Roadmap for Softmax Attention: Exact Born-Rule Analogs for Softmax Attention on the Probability Simplex
arXiv quant-ph
arXiv:2608.11173v3 Announce Type: replace Abstract: The attention mechanism forms the foundation of many modern AI models such as the Transformer. In one subclass of problems where attention is used, inputs and outputs are bound to the…
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SpinControl: Control Software for Prototyping and Benchmarking of Spin-Qubit Devices and Measurement Protocols
arXiv quant-ph
arXiv:2610.23316v1 Announce Type: new Abstract: Quantum computers require software to control the states of the qubits. As the actions on qubits grow in complexity with circuit execution, calibration, and benchmarking, the complexity of…
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Geometric heat pumping on a quantum processor
arXiv quant-ph
arXiv:2610.09062v2 Announce Type: replace Abstract: Geometric heat pumping is the transfer of energy between reservoirs at equal temperature where the heat exchanged in an adiabatic cycle depends only on the driving contour in parameter…
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Expressivity of IQP Feature-Map Quantum Kernels via Reproducing Kernel Hilbert Spaces
arXiv quant-ph
arXiv:2610.23692v1 Announce Type: new Abstract: Quantum kernels are among the most promising methods in quantum machine learning, providing a natural way to embed data into high-dimensional Hilbert spaces via quantum circuits and capturing…
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Time-dependent integrable quantum field theories with dynamical boundaries
arXiv quant-ph
arXiv:2610.03870v2 Announce Type: replace-cross Abstract: We present a general method to construct and solve time-dependent integrable chiral quantum field theories on finite intervals from autonomous scattering and reflection data…
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Task-aligned spectral inductive biases in parameterized quantum circuits
arXiv quant-ph
arXiv:2610.23834v1 Announce Type: new Abstract: Parameterized quantum circuits are widely investigated in quantum machine learning, yet how their architecture can provide task-aligned inductive biases remains poorly understood. We study…
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Impact of Irrep Truncations on Quantum Simulations of QCD
arXiv quant-ph
arXiv:2610.23681v1 Announce Type: cross Abstract: Quantum simulations of lattice gauge theories with continuous gauge groups require a choice of basis (how states of the gauge theory map to the qubit computational basis) and truncation…
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Noise structuring in fixed-depth Trotter simulation: stationary channels and observable-level depolarization
arXiv quant-ph
arXiv:2607.17936v2 Announce Type: replace Abstract: 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…
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Non-Monotonic Exciton Transport Efficiency in Multi-layer Ring-shaped Quantum Networks inspired by Photosystem I
arXiv quant-ph
arXiv:2610.13949v2 Announce Type: replace-cross Abstract: Photosystem I (PSI) is one of the most efficient natural photosynthetic complexes and serves as a structural prototype for understanding excitation energy transfer (EET) and…
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Quantum-Classical Neural Networks for Solving Lindblad Master Equations
arXiv quant-ph
arXiv:2610.22691v1 Announce Type: new Abstract: Variational quantum algorithms have emerged as a promising approach for simulating open quantum systems, yet their expressive power and trainability remain poorly understood. We propose a…
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Concrete Functions in Private Simultaneous Quantum Messages: Quantum Advantages and Structural Limitations
arXiv quant-ph
arXiv:2610.23090v1 Announce Type: new Abstract: Private simultaneous quantum messages (PSQM) provide a minimal model of noninteractive secure multiparty quantum computation, yet their communication complexity for concrete functions remains…
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Inverse Current in Coupled Transport: A Quantum Thermodynamic Model
arXiv quant-ph
arXiv:2405.01295v4 Announce Type: replace Abstract: The recent discovery of inverse current in coupled transport (ICC) in classical systems [Wang et al., Phys. Rev. Lett. 124, 110607 (2020)] -- where an induced current flows opposite to…
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Probability distribution analysis of the cascaded variational quantum eigensolver
arXiv quant-ph
arXiv:2605.00807v2 Announce Type: replace Abstract: The cascaded variational quantum eigensolver (CVQE) circumvents the need for iterative communication between the quantum and classical processing units that is necessary in the…
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Predicting Dynamics from Flows of the Eigenstate Thermalization Hypothesis
arXiv quant-ph
arXiv:2504.01073v3 Announce Type: replace Abstract: Analytical treatments of far-from-equilibrium quantum dynamics are few, even in well-thermalizing systems. The celebrated eigenstate thermalization hypothesis (ETH) provides a post hoc…
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A finite-shot mean-squared-error boundary for Richardson zero-noise extrapolation
arXiv quant-ph
arXiv:2605.08251v2 Announce Type: replace Abstract: Zero-noise extrapolation (ZNE) reduces the bias of noisy quantum-circuit measurements, but Richardson coefficients and shot splitting increase their statistical error. This paper…
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Exact minimum measurement dependence for faithful local deterministic models of multipartite GHZ-Mermin correlations
arXiv quant-ph
arXiv:2608.00124v2 Announce Type: replace Abstract: A local deterministic model can reproduce Bell-inequality violations only if the hidden state depends on the measurement settings. Hall found the minimum such dependence for the singlet…
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Fault tolerance of quantum circuits with tensor networks and symplectic geometry
arXiv quant-ph
arXiv:2610.03429v2 Announce Type: replace Abstract: We develop an operator-algebraic framework for analyzing fault tolerance in quantum circuits and establish necessary and sufficient conditions for exact recovery of the ideal computation…
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Photon-stimulated decay of $\chi$-matched ancillas causes unheralded bit flips in bosonic codes
arXiv quant-ph
arXiv:2610.17017v2 Announce Type: replace Abstract: Bosonic codes often read out their syndrome with a transmon ancilla whose computational levels $g$ and $f$ have equal parity and matched dispersive shifts: a decay $f\to e$ is then…
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A Rydberg atom array coupled to a high-cooperativity optical cavity
arXiv quant-ph
arXiv:2610.20889v2 Announce Type: replace-cross Abstract: Integrating Rydberg-state control of atom-atom interactions with cavity control of atom-light interactions enables the combination of local entangling operations with…
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Encodings and Node Architecture: Lessons from the Fault-Tolerant Distributed Transversal Fanout
arXiv quant-ph
arXiv:2610.22966v1 Announce Type: new Abstract: An encoding choice specifies the quantum error-correcting code used to encode logical qubits at a given node. Different encoding choices may differ in the number of physical qubits, the…
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Recursive Operator Localization and Spectral Gap Descent via the Geometry of Local Spectral Expansion
arXiv quant-ph
arXiv:2610.23695v1 Announce Type: new Abstract: We introduce Recursive Operator Localization (ROL), a framework for constructing hierarchies of local energy problems linked by linear maps between Hilbert spaces. To address spectral-gap…
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Cayley access models for matrix functions: reachable class and cost
arXiv quant-ph
arXiv:2610.23429v1 Announce Type: new Abstract: We study how to compute $f(A)b$ on a quantum computer, where $A$ is Hermitian. When $f$ is nonsmooth or has localized difficulty in the spectrum, classical numerical linear algebra…
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Sample-Based Quantum Linear Solver and Bounds on Krylov-State Sampling
arXiv quant-ph
arXiv:2610.23138v1 Announce Type: new Abstract: To solve linear systems $Ax=b$, we propose a sample-based quantum linear solver combining quantum Krylov-state sampling with classical variational diagonalization. Rather than simulating the…
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The Classical Boundary of Quantum Computation: History-Resolved Causal Stochastic Machines and the Cost of Classicalization
arXiv quant-ph
arXiv:2610.22750v1 Announce Type: new Abstract: What separates quantum computation from classical computation when a classical model may retain every branch history and arbitrary causal memory? We study this question using history-resolved…
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On the relationship between the POVM framework and the no-signaling hypothesis
arXiv quant-ph
arXiv:2610.22823v1 Announce Type: new Abstract: The quantum foundations literature contains dozens of "no-signaling" arguments that rely on the Born rule or, more generally, the positive operator-valued measure (POVM) framework to show…
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Improving the estimation of spin-bath parameters via initial correlations and a two-qubit probe
arXiv quant-ph
arXiv:2610.23582v1 Announce Type: new Abstract: We study how a second qubit can improve the estimation of spin-environment parameters when only one of the two qubits is measured. Both qubits are coupled to a common spin bath through the…
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Universal Threshold Laws for Dipolar Evaporation of Molecular Fermi Gases
arXiv quant-ph
arXiv:2610.22639v1 Announce Type: cross Abstract: Fermi statistics suppress the elastic collisions that rethermalize a Fermi gas during evaporative cooling, creating a fundamental low-temperature bottleneck for producing quantum degenerate…
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Temperature dependence of a warm ensemble based memory on quantum communication rates
arXiv quant-ph
arXiv:2610.23536v1 Announce Type: new Abstract: The success of long-distance quantum communication will hinge on quantum repeater nodes equipped with robust and scalable quantum memories. Such memories must possess specific operating…
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Temperature dependence of the Casimir force between plane-layered structures: an approach based on the principle of argument
arXiv quant-ph
arXiv:2610.23354v1 Announce Type: new Abstract: Based on the complex analysis theorem the principle of argument, a temperature-dependent formula for the Casimir-Lifshitz dispersion force of the interaction of two arbitrary plane-layered…
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Multiscale Quantum-Classical Simulation of Protein Autoproteolysis in a Million-Atom Membrane Environment
arXiv quant-ph
arXiv:2610.23108v1 Announce Type: cross Abstract: Predicting chemical reactions in biomolecules is challenging because reactive centers are embedded within complex environments that strongly influence their energetics and mechanisms. Here…
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Solving Large-Scale Parameter Inference in Controllable Nuclear Fusion via Coherent Ising Machines and Block Coordinate Descent
arXiv quant-ph
arXiv:2610.23507v1 Announce Type: new Abstract: Bayesian inference enables self-consistent plasma parameter inversion in tokamak integrated data analysis by fusing multi-source diagnostics. However, under nonlinear Gaussian likelihoods…
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Quantum approximate stochastic combinatorial optimisation
arXiv quant-ph
arXiv:2610.22876v1 Announce Type: new Abstract: Two-stage stochastic combinatorial optimisation concerns discrete decisions made before all relevant information is known. An initial decision is made; once uncertainty is resolved, it can be…
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Demonstration of Logical Error Suppression in a Surface Code Memory on a Cloud-Accessible IBM Superconducting Processor
arXiv quant-ph
arXiv:2610.23840v1 Announce Type: new Abstract: Quantum error correction can suppress logical errors exponentially with code distance when physical noise is below threshold. Realizing this on hardware requires tight coordination among…
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Continuous variable dense coding under realistic non-ideal scenarios
arXiv quant-ph
arXiv:2407.07609v2 Announce Type: replace Abstract: We analyze the continuous variable (CV) dense coding protocol between a single sender and a single receiver when affected by noise in the shared and encoded states, as well as when the…
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Phase-preserving steady-state operations beyond Lindblad master equations
arXiv quant-ph
arXiv:2510.10394v5 Announce Type: replace Abstract: We consider a class of nonunitary operations that is naturally implemented via a combination of projective measurement and unitary operators. We implement these operations without using…
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Evolution and breakdown of chiral anomaly in Weyl semiconductor tellurium
arXiv quant-ph
arXiv:2610.13084v2 Announce Type: replace-cross Abstract: Chiral anomaly in topological materials manifests as negative longitudinal magnetoresistance, yet the tunability and evolution of this effect remain elusive. Here we show that doped…
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Vanilla Exact Synthesis of CNOT Circuits is NP-hard
arXiv quant-ph
arXiv:2609.04160v3 Announce Type: replace Abstract: Exact CNOT synthesis seeks a minimum-size circuit implementing a given invertible binary linear transformation. We study its vanilla formulation: synthesis from the identity on fixed…
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Transport and thermalization under noncommuting localized constraints
arXiv quant-ph
arXiv:2610.23781v1 Announce Type: cross Abstract: We investigate the effects of spatially localized conserved quantities on transport and thermalization in quantum and classical many-body systems. We consider several related models: the…
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Characterization of Linear Measurements in Cavity Optomechanics: Examples and Applications
arXiv quant-ph
arXiv:2508.21419v2 Announce Type: replace Abstract: Detailed understanding of physical measurements is essential for devising efficient metrological strategies and measurement-feedback schemes, as well as finding fundamental limitations on…
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Higher-Dimensional Information Lattice: Quantum State Characterization through Inclusion-Exclusion Local Information
arXiv quant-ph
arXiv:2512.20793v2 Announce Type: replace Abstract: Developing a local description of quantum information is a central problem in quantum many-body physics: the goal is to identify how correlations are organized across positions and scales…
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Efficient LLM-Generated Shuttling Compilers for Complex Trapped-Ion Architectures
arXiv quant-ph
arXiv:2607.24714v2 Announce Type: replace Abstract: Trapped-ion quantum computers rely on shuttling compilers, which cast an input algorithm into a sequence of ion-qubit movements within a given architecture. We present the first study in…
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Resonant pair production and flat band melting in a driven Rydberg chain
arXiv quant-ph
arXiv:2610.22532v1 Announce Type: new Abstract: We study a Rydberg chain subjected to a two-tone periodic drive of the detuning $\Delta(t)$ and Rabi frequency $\Omega(t)$ at frequencies $\omega_1$ and $\omega_2=\nu \omega_1$ respectively…
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Bell scenarios encode classical non-causality
arXiv quant-ph
arXiv:2610.23367v1 Announce Type: new Abstract: Bell and contextuality scenarios are unified within the Ac\'in-Fritz-Leverrier-Sainz hypergraph formalism, in which measurements are hyperedges. Multipartite measurements are obtained from…
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Quality-of-Transmission Estimation in Quantum Networks: Compute, Simulate, or Learn?
arXiv quant-ph
arXiv:2610.23827v1 Announce Type: new Abstract: Future quantum networks will rely on control-plane decisions such as routing, scheduling, entanglement provisioning, purification, and memory allocation. Each decision depends on a timely and…
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Nonequilibrium Dynamical Quantum Phase Transitions in the Extended Agassi Model
arXiv quant-ph
arXiv:2610.23096v1 Announce Type: new Abstract: We investigate dynamical quantum phase transitions (DQPTs) in the extended Agassi model following sudden quenches of same level pairing ($\Sigma$), monopole-monopole ($\chi$) and cross level…
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Holographic two-point functions across a PT symmetry-breaking transition
arXiv quant-ph
arXiv:2610.23580v1 Announce Type: cross Abstract: In parity-time (PT)-symmetric non-Hermitian systems, an exceptional point, where eigenvalues and eigenvectors coalesce, typically separates a real spectrum from complex-conjugate…
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Spectral theory of energy-selective quantum search with Ising Hamiltonian phase oracles
arXiv quant-ph
arXiv:2606.03380v3 Announce Type: replace Abstract: We develop an exact spectral-response theory for the Grover-type iterate \(W_T=D_\xi\exp(-\mathrm{i} T H)\), in which the evolution generated by a diagonal Ising Hamiltonian is used…
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Anyonic Neural Network Wavefunctions
arXiv quant-ph
arXiv:2610.23815v1 Announce Type: cross Abstract: The macroscopic behavior of a non-interacting gas of Abelian anyons has remained unsettled for many decades. Prior numerical methods employing exact diagonalization in the continuum and on…
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Partial Stabilizer Learning under Fixed Commuting Constraints and the Absence of a Copy-Rate Discount
arXiv quant-ph
arXiv:2609.13923v2 Announce Type: replace Abstract: We consider an unknown pure stabilizer state of \(n\) qudits with a fixed prime local dimension \(p\), together with prescribed commuting Pauli observables. Rather than learning the whole…
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Entropy Production and Thermalization in Heavy-Quark Langevin Dynamics
arXiv quant-ph
arXiv:2610.22501v1 Announce Type: cross Abstract: Heavy quarks are often treated as Brownian probes of the quark-gluon plasma. We formulate the irreversible entropy balance of their momentum distribution and separate the production…
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Path-Degenerate Quantum Interferometry for Loss Resilience in Gravitational-Wave Detectors
arXiv quant-ph
arXiv:2609.12204v2 Announce Type: replace Abstract: Optical decoherence degrades quantum correlations in squeezed states of light, severely limiting the quantum-nondemolition (QND) sensitivity of gravitational-wave detectors. Here, we…
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Constrained dissipation and the lifetime of quantum many-body scars
arXiv quant-ph
arXiv:2610.22223v2 Announce Type: replace Abstract: We investigate the fate of quantum many-body scars in the PXP model subject to Markovian dissipation. We show that when local jump operators respect the same symmetries of the Hamiltonian…
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Failure of the mean-field Hartree approximation for a bosonic many-body system with non-Hermitian Hamiltonian
arXiv quant-ph
arXiv:2601.13038v3 Announce Type: replace Abstract: Mean-field Hartree theory is a central tool for reducing many-body dynamics to an effective one-particle evolution. This approximation has been employed when the Hamiltonian governing the…
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Experimental Demonstration of a Balanced Travelling Wave Parametric Amplifier
arXiv quant-ph
arXiv:2610.23810v1 Announce Type: cross Abstract: Superconducting travelling-wave parametric amplifiers (TWPAs) provide broadband gain, low added noise, and high dynamic range, making them attractive for applications requiring wide…
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MIP*=RE
arXiv quant-ph
arXiv:2001.04383v4 Announce Type: replace Abstract: We show that the class MIP* of languages that can be decided by a classical verifier interacting with multiple all-powerful quantum provers sharing entanglement is equal to the class RE…
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Nonergodicity from Hilbert-Subspace Cloning
arXiv quant-ph
arXiv:2610.23105v1 Announce Type: cross Abstract: We identify a class of nonintegrable quantum many-body systems composed of single Pauli strings that possess an extensive number of noncommuting local conserved quantities and exhibit…
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Optimal single-copy estimation of quantum state moments: why $\operatorname{Tr}(\rho^3)$ and $\operatorname{Tr}(\rho^4)$ are equally hard
arXiv quant-ph
arXiv:2609.37781v2 Announce Type: replace Abstract: Estimating nonlinear properties of an unknown quantum state with restrictive experimental accessibility is a fundamental problem in quantum learning. We study the sample complexity of…
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Tunneling Dynamics and Time Delay in Electron Transport through Time-Dependent Barriers with Finite-Bandwidth Reservoirs
arXiv quant-ph
arXiv:2507.20649v4 Announce Type: replace-cross Abstract: We study a model system consisting of a tunneling barrier driven by an external harmonic field and coupled to two leads with finite bandwidth. Avoiding Floquet expansions, we derive…
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Morse Bridge between Planar Kepler and Hyperbolic Landau Dynamics
arXiv quant-ph
arXiv:2607.01778v4 Announce Type: replace-cross Abstract: A common Morse Hamiltonian bridges the planar Kepler--Coulomb and hyperbolic Landau systems, linking flat electric dynamics to curved magnetic dynamics. A radial Liouville…
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Discrete time crystals and classical logic gates in coupled open Dicke models
arXiv quant-ph
arXiv:2610.23043v1 Announce Type: new Abstract: We investigate the dynamics of coupled discrete time crystals (DTCs) in the coupled Dicke model or Dicke dimer (DD) with dissipation. By numerically simulating the mean-field dynamics of the…
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QMBL: the Quantum Many-Body Leaderboard. A live record of published ground-state energies for lattice Hamiltonians
arXiv quant-ph
arXiv:2610.22387v1 Announce Type: cross Abstract: In condensed matter physics, scientists explore phase diagrams of matter through various methods (analysis, numerics, experiment) and achieve consensus when enough methods agree. The…
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Development of a fabrication-to-benchtop process for SiN-based quantum devices
arXiv quant-ph
arXiv:2610.22776v1 Announce Type: cross Abstract: Silicon nitride has emerged as a key material for the advancement of future quantum communication and computational devices. However, challenges persist in establishing a comprehensive…
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Analysis of Hydrogen Contamination in Al/AlOx/Al Josephson Junctions
arXiv quant-ph
arXiv:2603.14113v3 Announce Type: replace Abstract: Hydrogen contamination in Josephson junctions may contribute to device-to-device variability in superconducting qubits, yet its incorporation, location, and bonding in tunnel barriers…
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Low-Resource Quantum Energy Gap Estimation via Randomization
arXiv quant-ph
arXiv:2601.13881v3 Announce Type: replace Abstract: Estimating the energy spectra of quantum many-body systems is a fundamental task in quantum physics, with applications ranging from chemistry to condensed matter. Algorithmic shadow…
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Transverse momentum as the counter-diabatic generator in bent waveguide couplers
arXiv quant-ph
arXiv:2609.36431v2 Announce Type: replace Abstract: Bending the axis of a mode-evolution coupler suppresses the nonadiabatic coupling between its supermodes, and bent couplers of this kind were recently shown to realize the…
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Non-invasive 2D spatial measurements of electric fields within a plasma sheath
arXiv quant-ph
arXiv:2511.12322v2 Announce Type: replace-cross Abstract: We introduce an all-optical quantum-enhanced diagnostic for electric fields in low-temperature plasmas. Trace amounts of rubidium vapor, added to an argon plasma, allow us to employ…
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Quantum Tsallis Entropy Estimation: Near-Optimal Bounds and High-Precision Improvements
arXiv quant-ph
arXiv:2610.22983v1 Announce Type: new Abstract: Estimating statistical properties of probability distributions is a fundamental problem in statistics and theoretical computer science. We develop quantum algorithms for estimating the…
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Action-Quantized Scar Multiplets and Dissipative Cat States from Fractal Period-Locking in the Open Quantum Baker Map
arXiv quant-ph
arXiv:2610.23573v1 Announce Type: cross Abstract: We open the quantum baker map with a position window of width $w$ and center $q_c$. Classical pruning tiles the $(q_c,w)$ plane into diamonds where the $T$ leading resonances form…
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Hybrid boson sampling-neural network architecture for enhanced classification
arXiv quant-ph
arXiv:2510.13332v2 Announce Type: replace Abstract: Demonstration of quantum advantage for classical machine learning tasks remains a central goal for quantum technologies and artificial intelligence. Two major bottlenecks to this goal are…
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Risk-aware neural pulse compilation of continuously parameterized single-qubit gates with optimal-control benchmarking and NMR hardware validation
arXiv quant-ph
arXiv:2604.11314v3 Announce Type: replace Abstract: Pulse-level compilation can reduce the depth and calibration overhead associated with decomposing continuously parameterized quantum operations into fixed gate libraries, but conventional…
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Separability from Multipartite Measures
arXiv quant-ph
arXiv:2605.02097v3 Announce Type: replace Abstract: We show that multi-invariants provide necessary and sufficient criteria for full separability in finite-dimensional multipartite systems. For tripartite three-qubit states, the…
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Caustics and catastrophes in strong-field physics $-$ Picard-Lefschetz theory as a universal approach to saddle-point methods in attosecond science
arXiv quant-ph
arXiv:2605.03794v2 Announce Type: replace Abstract: Ultrashort laser pulses on the attosecond timescale are typically achieved via high-order harmonic generation (HHG), a nonlinear process in which atoms interact with intense light fields…
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Molecular Ground State Simulation by Subspace Restriction and Hund's Rule
arXiv quant-ph
arXiv:2404.03268v4 Announce Type: replace Abstract: The Subspace Restriction Scheme (SRS) is presented to address the qubit and resource constraints of molecular simulation on near-term quantum hardware. SRS restricts a molecular…
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Liouvillian Non-Invertible Symmetry
arXiv quant-ph
arXiv:2610.23111v1 Announce Type: new Abstract: Non-invertible symmetries extend conventional symmetries beyond group-like transformations and play an important role in quantum field theory and many-body physics. However, a general…
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Dominant Eigenstate Isolation through Symmetry-Orbit Decoupling
arXiv quant-ph
arXiv:2606.21962v2 Announce Type: replace Abstract: We address the problem of extracting a target eigenstate from an approximate pure state. Our approach, symmetry-orbit decoupling, exploits symmetries that preserve the target state while…