September 10, 2026

Loss-correcting fault-tolerant quantum computing architecture for neutral atomsTier 3

Neutral-atom arrays are a leading qubit technology for large-scale, fault-tolerant quantum computing (FTQC). A dominant error source on this platform is qubit loss, which accrues with every operation and movement. The presence of loss undermines the promises of existing architectural work. Standard error correction targets stochastic Pauli errors and cannot correct loss, so...

Xanadu and ASML Partner to Optimize Lithography Processes for Ultra-Low-Loss Quantum PhotonicsTier 2

Xanadu Quantum Technologies and ASML are collaborating to improve lithography processes for quantum photonics, aiming to reduce optical signal loss in silicon photonic circuits. Their research focuses on minimizing Line Edge Roughness (LER) caused by DUV and EUV photolithography, which scatters photons in optical waveguides, with the goal of achieving ultra-smooth wavegui...

Previously: 2026-09-01

Accelerating A*-Based Algorithms for Decoding Quantum Low-Density Parity-Check CodesTier 3

Quantum low-density parity-check (QLDPC) codes represent a promising approach for error correction in quantum computing. The recently proposed Tesseract decoder uses the A* search algorithm that guarantees finding the most likely error pattern. However, practical implementations of Tesseract often involve an extremely large graph, and the inherently sequential nature of the...

Electrically tunable, two-photon interference from remote silicon-vacancy centers in industrial silicon carbideTier 3

Distributed quantum networks rely on spatially separated, independently operated quantum systems as network nodes, whose emitted photons must be interfered with high visibility to establish end-to-end entanglement. Crucially, for network-relevant applications, high visibilities must be achieved over prolonged timescales to reduce overheads for error correction, and to increa...

Programmable photonic state fusion via heralded storage of asynchronously generated resourcesTier 3

Probabilistic photonic sources generate elementary states in different trials, whereas multiphoton protocols require them to interfere in common temporal modes. We propose a fusion protocol that overcomes this mismatch by successively loading independently heralded photonic states into active storage loops. Conditioning on vacuum in monitored dump modes selects events in whi...

Non-equilibrium dissipative stabilization of s- and d-wave superconductivityTier 3

Stabilizing superconductivity beyond its equilibrium regime has been one of the quests of nonequilibrium state engineering. We report the presence of nonthermal pairing gap in BCS superconductors coupled to two thermal baths, where one of the baths can be at a temperature well above the equilibrium T_c. Superconducting state is enabled by a highly non-equilibrium steady st...

Quantum computational resources and validation protocols for a three-mode non-Gaussian trilinear HamiltonianTier 3

Non-Gaussian interactions are a key ingredient for achieving universality in continuous-variable quantum computation, yet their experimental characterization and the validation of their correct implementation remain challenging tasks. In this work, we focus on a three-mode non-Gaussian trilinear Hamiltonian that has recently been realized in superconducting microwave platfor...

Coded Clifford Measurements for Multiqubit Magic-State CultivationTier 3

Magic-state cultivation suppresses errors by measuring logical Clifford symmetries and discarding inconsistent outcomes. For an entangled resource several branches are accepted, so the retained branch carries a multibit classical record whose corruption produces a logical-frame error. We show that this record layer is exactly a binary linear code. For any third-level Cliffor...

UC Berkeley Welcomes QuantrolOx to its Quantum Innovation CorridorTier 2

UC Berkeley's Roger Herst Quantum Nexus has welcomed QuantrolOx, a UK-headquartered qubit automation startup, establishing its first North American base. This partnership, solidified by a five-year MOU, integrates QuantrolOx's Quantum EDGE software with UC Berkeley's quantum processing units to automate qubit tuning and calibration, aiming to standardize hardware pipeline...

Coherent advantage in the computational expressivity of excitonic networksTier 3

The rising energy consumption of AI has generated interest in physical systems as alternative substrates for trainable computation. Recent experimental advances have enabled precise control over the couplings between molecular chromophores, which give rise to coherent excitation dynamics. Here, we study driven-dissipative excitonic networks as a computational platform, where...

Fidelity-Aware Scheduling of Quantum Circuits on Multi-QPU SystemsTier 3

High Performance Computing-Quantum Computing (HPCQC) platforms expose multiple Quantum Processing Units (QPUs) that may differ in size, topology, native gates, and noise characteristics. For current noisy devices, errors compound along the compiled circuits quickly, and minimizing them, that is, maximizing the circuits' execution fidelity, is essential for reliable results....

Guest Post: Why Enterprises Need to Start Post-Quantum Migration NowTier 2

The Sample Complexity of Quantum Entanglement AllocationTier 3

How many past requests are needed to decide which qubits should share entanglement? We show that the answer depends on the allocation choices created by the queries: a larger memory can require no more data. The memory stores a classical bit and answers requests through a fixed detector that preserves coherence within each measured sector. For independent commuting X- and...

NVision Advances EuroHPC QOSMOS Project for Photonic-Interfaced Spin QubitsTier 2

NVision Quantum Technologies has received €293,455 in Phase 1 funding from the EuroHPC Joint Undertaking for its QOSMOS project, aimed at developing a Photonic-Interfaced Quantum Computer (PIQC) architecture. This funding will support the creation of a roadmap for scaling their spin-qubit technology, which uses photonic integrated circuits to overcome scaling limitations....

Quobly and Absolut System Execute Industrial Cryogenic Roadmap for Silicon Spin-Qubit ComputersTier 2

Quobly and Absolut System have partnered to develop advanced cryogenic infrastructure for silicon spin-qubit computers, successfully qualifying the QCube® 100-Class 3 platform. This system provides 100 mW cooling at 500 mK, essential for Quobly's integrated control logic architecture, paving the way for scaling to one million qubits by 2032. This collaboration, supported...

Information capacity of quantum statistics: Fock-state tests of a discrete binary-sequence model on cloud photonic quantum processorsTier 3

Our central premise is that quantum mechanics may be the statistical limit of a more fundamental discrete theory: any such theory equips a physical system with a finite information capacity, and its departure from quantum statistics is controlled by how much of that capacity the system uses. We show that commercial cloud photonic quantum processors have reached the precision...

La Luce Cristallina Launches Quantum Paraelectric Strontium Titanate on Insulator Wafer PlatformTier 2

La Luce Cristallina has launched its 0.5-micrometer silicon-based quantum paraelectric strontium titanate on insulator (QP-STOI) wafer platform. This platform is designed for quantum computing, cryogenic electronics, and non-linear electro-optic architectures, offering a foundry-compatible substrate that exploits strontium titanate's dielectric tunability at liquid-helium...

IBM, Lockheed Martin Announce Swiss Quantum Innovation Hub at ETH Zurich, Anchored by Switzerland’s First IBM Quantum ComputerTier 2

Former Google Executive Gina Fratarcangeli Joins Qtonic QuantumTier 2

For Whom Does Bell Hold?Tier 3

Violations of Bell's inequalities offer a definitive signal of non-classical (quantum) behavior in local deterministic systems. Yet, in many physical settings where quantum mechanics is expected to play an important role, one cannot construct a Bell-type test using the available observables. Cosmology offers one concrete example, where cosmic structure may have originated fr...

Noether Symmetries Generate Deterministic Energy-Harvesting ProtocolsTier 3

We consider the general principles for when deterministic energy harvesting (DEH) is possible. DEH means absorbing energy from a fluctuating source without entropy being absorbed. We show that the symmetry structure of the source--harvester dynamics gives a general route beyond existing examples to identify DEH capable source states. Any continuous symmetry with a conserved...

Optimal Low-Rank Quantum State Tomography with Bounded-Sample Joint MeasurementsTier 3

We determine the optimal sample complexity of low-rank quantum state tomography when each measurement may act jointly on at most t samples. For sufficiently small ε, estimating an unknown state on C^d of rank at most r to trace norm error ε with constant success probability requires, and is achievable with, $Θ( dr/varepsi...

Phase transitions in first-detection statistics of monitored long-range quantum walksTier 3

In a quantum walk, the first-detection return probability (FDRP) characterizes salient features, determining whether the quantum walk is transient or recurrent. We study the FDRP of quantum walks on a chain where the initial site is stroboscopically monitored by a detector and the walker performs long-range hopping between sites. We assume that the hopping strength decays wi...

Quantum Feature Engineering for Credit Default Prediction: When and Why IQP Circuits Help Linear ClassifiersTier 3

Credit default prediction is a tabular classification problem in which modest gains in F1 translate directly into reduced financial exposure. We ask whether Instantaneous Quantum Polynomial-time (IQP) circuits can produce features that improve a classifier over both its raw classical baseline and Kernel PCA - the strongest unsupervised classical non-linear alternative - at a...

Faster Quantum Monte Carlo Simulation by Random CompilationTier 3

Quantum Monte Carlo (QMC) algorithms are among the most powerful classical methods for simulating quantum systems, yet their accuracy is often limited by the systematic errors in the approximations used, such as Trotterization. Here we introduce randomly compiled quantum Monte Carlo (RC-QMC) as a general framework that suppresses these systematic errors by averaging over a f...

Symmetry structure dependent diagnostic of the Quantum Mpemba EffectTier 3

Understanding symmetry restoration in isolated quantum many-body systems is an important problem in nonequilibrium many-body quantum physics. Recent studies have shown that the quantum Mpemba effect can be characterized through entanglement asymmetry, where states with stronger initial symmetry breaking restore symmetry faster. However, it remains unclear whether conventiona...

Faster Computation with the Generalized Laplacian Quantum WalkTier 3

Quantum walks are the quantum analogues of classical random walks or Markov chains. They are universal models of quantum computing, and they underpin a variety of quantum algorithms. We prove that a continuous-time quantum walk effected by a generalized Laplacian, which can arise in spin chains, can solve a computational problem more quickly than typical quantum walks govern...

Noncommutative sharp Hausdorff-Young inequalityTier 3

We prove the sharp Hausdorff--Young inequality on the quantum Euclidean space. Meanwhile, our result implies the sharp Hausdorff-Young constants for the Weyl transform, as well as that for the Heisenberg group. The key ingredient is a novel operator-valued flow related to the Gabor transform. Our method is mainly based on operator calculus and hence generally applicable to s...

Field quantization in rotating frames: coordinate covariance and the circular-detector responseTier 3

We provide a unified analysis of scalar-field quantization and detector response in relativistic rotating frames, comparing rigid and Trocheris-Takeno (TT) descriptions in unbounded Minkowski spacetime. We distinguish three questions that are often conflated: (i) how a fixed quantum state is represented in rotating coordinates, (ii) whether rotating time evolution selects a...

Quantifying Information Hierarchy for Neutrino Oscillation Parameters at JUNOTier 3

Since neutrinos are quantum systems inherently, the precision with which oscillation parameters can be estimated ultimately depends on how much information about these parameters is encoded in the neutrino state and how efficiently that information can be extracted through measurement. In this work, we quantify how information encoded in reactor antineutrino states flows thr...

On the Limits of Quantum Multiparty Simultaneous CommunicationTier 3

The Simultaneous Message Passing (SMP) model provides a fundamental framework for comparing classical and quantum communication. For two players, Gavinsky et al. (STOC 2006) established a separation underlying the incomparability of shared randomness and quantum communication: \textsc{Index Coordination} needs O(log n) public-coin bits but Ω(n^(1/3)) bounded-error qubit...

Solving wave propagation problems via geometric quantum state preparation on dispersion manifoldsTier 3

We present a quantum algorithm for solving partial differential equations through a linear-system formulation, focusing on wave propagation problems described by the discretized Helmholtz equation in frequency domain. Although quantum linear-system solvers offer exponential compression of the system degrees of freedom, their runtime complexity is generally governed by the co...

An analysis of iterative refinement for quantum linear system solversTier 3

We present and analyze an iterative refinement (IR) framework for improving the precision dependence of algorithms that combine a quantum linear system algorithm (QLSA) with quantum state tomography. Existing QLSAs achieve polylogarithmic dependence on the inverse error tolerance to prepare a quantum state encoding the solution, but extracting a classical description of such...

Finite-Particle Quantum Reduction of Thermodynamic IrreversibilityTier 3

Thermodynamics is useful because it lets us predict and control complex systems from a few accessible quantities when microscopic reconstruction is impractical. We ask whether this operational reduction can be less costly in a finite quantum system than in a matched classical one. We compare a few-boson Bose--Hubbard chain with its number-conserving classical-field counterpa...

BRST quantization for the restoration of broken symmetries: a pedagogical exampleTier 3

We present a pedagogical showcase of BRST quantization for restoring symmetries in nuclear many-body systems as a reformulation and potential alternative to conventional projection methods. The formalism is illustrated using translational invariance for a simple system of two interacting masses in one dimension, but with an eye toward generalizing to more particles, higher d...

Unbounded degree overhead for Alice-conditioned quantum Bell certificatesTier 3

Requiring each sum-of-squares term to involve only one of Alice's measurement questions can impose an unbounded certification cost. In the simplest Bell scenario, we prove that no finite level of the Alice-conditioned NPA hierarchy contains all standard level-two Bell certificates. An explicit family of truncated positive functionals on the infinite dihedral group exceeds th...

Quantum Barankin bounds beyond local unbiasedness: Analytic results for Gaussian states via a right-division frameworkTier 3

We propose a quantum version of the Barankin bound as an alternative to the quantum Cramér-Rao bound for quantum parameter estimation. The quantum Barankin bound provides a lower bound on the mean squared error of estimators satisfying arbitrarily chosen bias constraints at arbitrarily chosen parameter points. In particular, unbiasedness over the entire parameter space can b...

Multiparameter quantum bounds for entanglement-assisted aperture synthesisTier 3

Entanglement-assisted optical interferometry promises diffraction-limited imaging over baselines where light cannot be physically combined, but existing theory treats only a single visibility on one two-station baseline. This work formulates the multiparameter estimation problem for an M-station array imaging an extended scene. A reduction lemma shows that the multimode quan...

In situ characterization of a photon-subtraction device via heralding counts and homodyne detectionTier 3

Photon subtraction is one of the most important techniques for generating non-Gaussian optical states and constitutes a key resource for quantum information processing and quantum metrology. The practical performance of a photon-subtraction device is primarily determined by the transmissivity of the beam splitter and the quantum efficiency of the heralding detector. Accurate...

Why three? A two-level system with four mutually unbiased questionsTier 3

Two sharp yes/no questions are mutually unbiased if and only if their involutions anticommute. A set of unbiased questions is therefore a Clifford algebra, whose maximal size is odd, meaning four anticommuting questions typically imply a fifth: the two-level systems of real, complex and quaternionic quantum theory allow two, three and five questions, while four is skipped. W...

Haar-Bayesian Pure-State Prediction under Relative-Entropy Loss: Arbitrary-Effect Reduction and Global OptimalityTier 3

We study Haar-Bayesian prediction of one unmeasured copy of an unknown finite-dimensional pure quantum state after an arbitrary collective measurement on n observed copies. Performance is evaluated by quantum relative entropy. For a fixed measurement, the Bayes predictive state is the posterior mean and the optimized conditional loss is its entropy. We then optimize the me...

Semi-device-independent quantum randomness certification in semiconductor spin-noise measurementsTier 3

Complex solid-state systems are promising platforms for scalable, high-bandwidth quantum random-number generation, yet certifying the quantum origin of their fluctuations remains difficult because the underlying microscopic dynamics are hard to model and validate. Here we demonstrate semi-device-independent quantum randomness certification from semiconductor spin noise, to o...

One Relative Phase Orders Operational Thresholds of Noisy Bell PairsTier 3

Unlike the two-qubit entangled and CHSH-nonlocal sets, the steerable and Bell-nonlocal ones have no known general closed-form criterion. For any such operational ability whose failing states form a convex set closed under local unitaries, and for a Bell mixture with arbitrary noise, the X part of the noise gives an upper bound on the definitive threshold, the Bell weight a...

Entanglement Entropy of Interacting Scalar Theories on Fuzzy SpacesTier 3

We investigate the impact of self-interactions on the Rényi and entanglement entropies of a scalar field on (2+1)-dimensional spacetimes, whose spatial sections are modeled by fuzzy spaces, specifically the fuzzy sphere and the fuzzy disc. We compute the first-order perturbative correction induced by a λφ^4 interaction using the Green's function approach. In contrast to...

A Separation between Full-Rank PVM and Assumption-free Self-TestingTier 3

We construct a nonlocal game that self-tests a maximally entangled qubit strategy among pure full-Schmidt-rank projective strategies, but admits an inequivalent optimum using one nonprojective measurement. This resolves a conjecture of Baptista et al. on imposing full rank and projectivity simultaneously. The construction combines CHSH with an auxiliary game G that forces...

SIM-GRAPH: A universal guide to symmetric interactionsTier 3

Symmetry plays a central role throughout physics, from Fourier analysis on discrete lattices to the classification of elementary particles in the standard model. In finite quantum systems, symmetries are often discrete, such as reflection and rotational symmetries. Here, we present the SIM-GRAPH method (Symmetric Ising Models - Graph Reduction And Projected Hamiltonians), wh...

From Block-encoding to Generalized Quantum Signal Processing: Principles, Algorithms and ApplicationsTier 3

Modern quantum algorithms are increasingly formulated as coherent procedures for implementing polynomial transformations of operators and singular values. This perspective provides a powerful and unifying language for quantum algorithm design, connecting a wide range of distinct problems through five closely related key tools: block-encoding, qubitization, QSP, QSVT and GQSP...

Revealing the Quantum Signature of Gravity via Gravitational WavesTier 3

Can propagating gravitational waves serve as operational probes of the quantum nature of gravity? We address this question by developing a unified theoretical framework that combines spacetime geometry, quantum information, and gravitational-wave physics. Starting from the geodesic deviation equation in linearized General Relativity, we derive the effective detector Hamilton...

When Does a Quantum Speedup Survive End-to-End?Tier 3

Primitive quantum speedups are interface-relative: they depend on the input access used to run the primitive and on the output contract used to consume its state or samples. This paper introduces a transcript-level admissibility relation A_Mpreceq_(int)A_Q, defined relative to the declared implementation package of the quantum interface. It identifies which ada...

Simple QKD keyrate computations from tangent-line boundsTier 3

Recent work in quantum key distribution (QKD) has yielded finite-size keyrates based on convex optimisation problems, using the framework of entropy accumulation. Multiple solvers have been developed to address these optimisations in recent years, but have been based on a somewhat elaborate framework using sophisticated algorithms, in order to accommodate a broad range of QK...

Minimax games for quantum channel discriminationTier 3

Quantum channel discrimination is a primitive task for identifying, verifying, and benchmarking quantum dynamics. Previous studies have primarily considered either the best-case tester-input setting or the worst-case jammer-input setting. Here, we introduce a game-theoretic framework in which both the tester and jammer control separate inputs. Combining three input structure...

Robust Device-Independent Certification of Boolean-Phase GatesTier 3

Device-independent certification of a quantum gate requires the input and output tests to identify the same reference qubits. Self-testing the output Choi state alone does not guarantee this consistency. We develop a robust certification scheme for Boolean-phase gates, a broad family of computational-basis diagonal gates specified by Boolean functions. Boolean derivatives co...

Dynamic Observable Subspaces: Fast Simulation of Observable Quantum DynamicsTier 3

By decomposing quantum dynamics across the Lie orbits of a list of observables, we find polynomial bounded classical simulations for the dynamics of the quantum system given a polynomial sized dynamic Lie algebra (DLA) for the generators of the quantum system. To do so, we describe how to construct the Dynamic Observable Subspace (DOS) that captures all the relevant dynamics...

Keyfactor Surpasses $200 Million ARR Amid Enterprise Post-Quantum Migration SurgeTier 2

Keyfactor has surpassed $200 million in annual recurring revenue in Q3 2026, driven by a 35% year-over-year growth and increasing demand for enterprise trust infrastructure due to post-quantum cryptography migration. This growth is further bolstered by a $1 billion+ investment from Summit Partners and the intent to acquire Cofide, enhancing Keyfactor's capabilities in mac...

SandboxAQ and Northrop Grumman Flight-Test AQNav Quantum Navigation on Attritable DroneTier 2

SandboxAQ and Northrop Grumman successfully flight-tested the AQNav magnetic navigation system on a Lumberjack® attritable drone, marking the first operational flight-test of MagNav on an expendable platform and the first pairing of magnetic anomaly navigation with visual navigation sensors on a one-way attack system. This demonstration validated AQNav's software-first ar...

SEALSQ Expands Quantum Highway to Nine Hubs Across Four CountriesTier 2

a16z Crypto Rebuilds Jolt Proof System With Post-Quantum Security And Faster PerformanceTier 2

SandboxAQ Tests GPS-Free Navigation on Northrop Grumman DroneTier 2

Keyfactor Surpasses $200 Million in Annual Recurring RevenueTier 2

Guest Post: What CERN Brings To QuantumTier 2

Information Causality Characterizes the Set of Quantum Correlations in the Simplest Bell ScenarioTier 3

Information causality (IC) was introduced as a physical principle constraining correlations in non-signaling theories. Whether it can recover the exact quantum correlation boundary, beyond Uffink's inequality, has remained an open question. Here, we combine its generalized formulation for correlated inputs with a new communication protocol to derive quantum Bell inequalities...