September 25, 2026

Design Principles for Ultra-High-Rate Quantum CodesTier 3

Reducing the qubit overhead of quantum error correction is a central challenge for scalable fault-tolerant quantum computing. Recent ultra-high-rate quantum codes offer a promising route toward this goal, with some constructions requiring as few as two physical data qubits per logical qubit. However, systematic principles for navigating the tradeoffs among encoding rate, dis...

Non-Abelian sheaf quantum LDPC codes: good and magicalTier 3

Non-Abelian quantum codes connect quantum error correction, phases of matter, and computational resources. In this work, we develop a general framework for constructing non-Abelian quantum low-density parity-check (qLDPC) codes by gauging sheaf codes via cup products and use it to obtain families with constant encoding rate and linear distance. We resolve the coupled logical...

Syndrome measurements enable deterministic fault-tolerant T gatesTier 3

Non-Clifford gates are essential for universal quantum computation, yet implementing them fault-tolerantly remains a central challenge for stabilizer codes. Here, we show how a syndrome degree of freedom can mediate a logical non-Clifford gate. Releasing one stabilizer check makes an additional logical qubit available within the encoded data block. Two Pauli rotations, follo...

Infleqtion Achieves 30 Entangled Logical Qubits on Its Sqale Quantum ComputerTier 2

Insider Brief PRESS RELEASE — Infleqtion (NYSE: INFQ), a global leader in quantum computing and quantum sensing powered by neutral-atom technology, today announced it has achieved 30 entangled logical qubits using just 80 physical qubits on its Sqale™ quantum computing platform, delivering a key milestone on its 2026 roadmap. This achievement makes Infleqtion the first...

Previously: 2026-08-25

Efficient Synthesis of Multi-Controlled Toffoli Gates with Ternary Clifford+P_9 GatesTier 3

Temporary occupation of qutrit levels can reduce the width and depth required for binary circuit logic in quantum computing. We introduce an efficient intermediate-qutrit decomposition of multi-controlled Toffoli gates with binary-subspace inputs and outputs. For balanced control widths n=2^h-1, the proposed decomposition is evaluated hierarchically through a tree, allowin...

100 million photons per second from a single organic moleculeTier 3

At cryogenic temperatures, organic single-photon sources (SPSs) offer Fourier-limited emission, virtually unlimited photostability, and emission wavelengths selectable by molecular design, making them attractive for quantum metrology, secure communication, and photonic quantum information processing. However, their efficient integration with photonic microstructures has rema...

A low-temperature entropy source for on-chip true random number generation: universal robustness beyond device qualityTier 3

True random number generation is a critical capability for fault-tolerant quantum computing at millikelvin temperatures. Yet existing Josephson-junction-based TRNGs all rest on a widely accepted but untested assumption: that reliable entropy extraction requires precisely controlled device parameters. Here we show that this assumption does not always hold. We demonstrate a co...

MagiCFirm: A Runtime for Magic-State Cultivation with Algorithm-Hardware Co-DesignTier 3

Magic-state cultivation offers a promising alternative for lowering the cost of non-Clifford operations in fault-tolerant quantum computing (FTQC). However, realizing cultivation in practice exposes two challenges: (i) the lack of an open-source classical runtime layer between logical software and physical control, and (ii) the latency constraints on protocol-specific decisi...

Learning and interpreting policies for simultaneous entanglement requests in quantum networksTier 3

Future quantum networks will make use of entanglement to perform numerous tasks, such as sending quantum information over long distances, distributed quantum computing, and quantum sensing. In general, these tasks will need to be performed simultaneously in various regions of a network, while minimizing resources and latency. We will thus require policies for scheduling link...

Quantum Feature Selection for Biomedical Data AnalysisTier 3

Feature selection is an essential step for reducing complexity of high dimensional data, usually in preparation for developing machine learning models such as computational biomarkers. However, there are limitations associated with feature selection such as for metabolomic data where there are hundreds or even thousands of features per study participant, while the available...

Collective thermalization, work reliability, and resource bounds in a population-inverted Dicke Otto engineTier 3

Population inversion and collective relaxation can both enhance the performance of a quantum heat engine, but through distinct mechanisms. We study a quantum Otto engine whose working medium is a symmetric collective spin of N two-level constituents. For commuting work strokes and collective reservoir coupling, the dynamics reduces exactly to a finite birth--death process...

MQSS-Selector: RL-Guided Pass Selection for an MLIR Compilation PipelineTier 3

High Performance Computing (HPC) and Quantum Computing (QC) systems are increasingly converging towards unified High Performance Computing-Quantum Computing (HPCQC) infrastructures, driven by a growing need to bridge classical and quantum workflows, which affects all levels of the system stack, from the hardware to compilers and runtimes, all the way to applications. However...

Leg-Tied Tensor Network States: Entanglement Beyond Virtual BondsTier 3

We introduce a class of tensor-network states in which physical legs are shared among local tensors, termed leg-tied tensor ansätze (LETTA). Physical leg ties encode long-range correlations directly, while a virtual matrix product state (MPS) backbone retains short-range multipartite entanglement. The linear virtual backbone allows us to develop a deterministic density matri...

A Block Decomposed QUBO Workflow for Chromosome-Y Phylogeny ReconstructionTier 3

This paper sets out a computational workflow that reconstructs the phylogeny of human Y-chromosome populations from a Variant Call Format (VCF) file of biallelic Single Nucleotide Polymorphisms (SNP). The two classical phylogenetic decisions - topology selection and root placement - are cast as Quadratic Unconstrained Binary Optimisation (QUBO) problems. The workflow combine...

QaiJi IR: An Eight-Layer Intermediate Representation Family for Hybrid Quantum-Classical CompilationTier 3

Hybrid quantum-classical compilers exchange programs among circuit, control-flow, pulse, device, and physical representations. Existing formats make different abstraction choices, so the properties that must survive a lowering step are often enforced by tool-specific code rather than stated in a common intermediate representation (IR). We present QaiJi IR, an eight-layer fam...

Evaluation-efficient quantum architecture search with ZX-calculus-based topological reuseTier 3

Variational quantum algorithm is a leading approach for quantum chemistry and many-body physics on noisy intermediate-scale quantum devices. The performance depends strongly on the structure of the parameterized quantum circuits. Quantum architecture search (QAS) can automate ansatz design. However, it requires repeated training and evaluation of many candidate circuits, lea...

Mesa Quantum Raises $11.8 Million to Scale Quantum Timing SystemsTier 2

Insider Brief PRESS RELEASE — Mesa Quantum, the company developing the next generation of quantum sensing technology for integration at scale, today announced it has raised $11.8 million in funding led by Playground Global. The round accelerates the company’s transition from component-level development to the full system integration and scaled production of deployable...

Trading Circuit Depth for Pulse Sparsity in Chromatic Dynamical DecouplingTier 3

Suppressing decoherence and crosstalk systematically across large networks of qubits is a pressing concern as qubit counts increase rapidly. General multi-qubit dynamical decoupling (DD) has historically been based on Hadamard matrices and orthogonal arrays, with instantaneous-pulse sequences whose circuit depth scales linearly with the number of qubits. Chromatic-Hadamard D...

Bifrost Electronics Appoints Doug Campbell as CEOTier 2

Insider Brief PRESS RELEASE — Bifrost Electronics, a leading developer and manufacturer of advanced electronic hardware for quantum computers, today announced that successful deep-tech entrepreneur Doug Campbell has joined the company as its Chief Executive Officer. Campbell brings more than two decades of start-up leadership in commercial electronics, aerospace system...

Pasqal Receives EIC Fund Award at 2026 TechEU Equity SummitTier 2

Insider Brief PRESS RELEASE — Pasqal (Nasdaq: PSQL), a global leader in neutral-atom quantum computing, today announced that it had received a European Innovation Council (EIC) Fund Award at the 2026 TechEU Equity Summit in Luxembourg. Organized by the European Investment Bank (EIB), the event explored market trends, investment needs and key challenges across deep ...

Oxford Quantum Circuits Appoints Simon Phillips as Chief Product OfficerTier 2

Insider Brief PRESS RELEASE — OQC, a global leader in quantum computing, today announced that Simon Phillips will move into the role of Chief Product Officer, having previously served as Chief Technology Officer. In his new role, Phillips will lead OQC’s product strategy, helping translate the company’s technology roadmap into enterprise-ready products designed to acce...

IonQ to Deploy Superion 256 Quantum Computer at Florida International UniversityTier 2

Insider Brief PRESS RELEASE — IonQ (NYSE: IONQ), the world’s leading full-stack quantum platform and foundry, today announced a contract with Florida International University (FIU), Miami’s top ranked state university. Under the agreement, IonQ will deliver its Superion 256-qubit trapped-ion quantum computer for installation at FIU. This contract establishes FIU as Ion...

Previously: 2026-09-22, 2026-09-19, 2026-09-09

Tezos Launches Quantumnet Post-Quantum TestnetTier 2

Insider Brief PRESS RELEASE — Engineering teams in the Tezos ecosystem have successfully launched Quantumnet, an experimental post-quantum testnet that previews an early post-quantum version of the Tezos network. Developers at Nomadic Labs, Trilitech, alongside other contributors, collaborated on the code for the experimental environment, which is designed to let netwo...

One-shot Routing in Quantum NetworksTier 3

Distributed quantum computation requires many entangled pairs to be available simultaneously, so routing must optimize fidelity from a fixed, short-lived set of network resources rather than the rate of pairs accumulated over time. We formulate this one-shot routing problem for heterogeneous Werner-state links and jointly optimize path selection and the schedule of entanglem...

memQ Releases Open-Source Distributed Quantum CompilerTier 2

Insider Brief PRESS RELEASE — memQ™, the industry leader in quantum networking for scalable and distributed quantum computing, announced today the public release of its distributed quantum compiler (DQC). This integral part of a distributed quantum computing environment will be released as a publicly available, open-source offering available on GitHub. memQ’s DQC is a...

Quantum Channel Stein Theorem beyond Definite Causal OrderTier 3

Distinguishability is a central concept in information theory and extends naturally to quantum systems. This work shows that, for any two finite-dimensional memoryless quantum channels, parallel, adaptive and general testing strategies achieve the same Stein exponent at every fixed type-I error tolerance ε∈(0,1), namely the regularized channel relative entropy. When this...

How Not to Build MicrocryptTier 3

A key challenge in quantum cryptography is to build quantum one-wayness and pseudorandomness without the use of (quantum computable) one-way functions. So far, this has turned out to be a difficult task, with only a few proposed candidates that are not directly built from one-way functions. Even within these few proposed candidates, we have lacked the techniques to analyze w...

Deep thermalization and Hilbert space ergodicityTier 3

Recent advances in quantum simulation have enabled the discovery of novel forms of universality in quantum many-body dynamics. In this Review, we discuss deep thermalization and Hilbert space ergodicity--two recently discovered phenomena characterized by the emergence of distributions of quantum states that are "maximally random" in a precise sense. They offer a new perspect...

The Moreau-Yosida approximation of the Entanglement of Formation: basic properties and accuracy estimatesTier 3

We describe a family of convex uniformly continuous functions E^λ_F, λ>0, on the set of states of a bipartite quantum system (consisting of finite-dimensional or infinite-dimensional subsystems), which monotonically increase and converge pointwise to the Entanglement of Formation (EoF) as λ→0. These functions are "nonselective" entanglement monotones defined by the w...

Optimal spectrum estimationTier 3

We prove that the spectrum of an unknown d-dimensional quantum state can be estimated to error ε in total variation distance using O(d^2min{ 1/((εlog d)^4), 1/((εlog d)^2) }) copies. This matches the recent lower bound of Wang. When restricted to unentangled measurements, we give an algorithm...

Sharp universal death of entanglement threshold for Pauli HamiltoniansTier 3

We determine the exact universal high-temperature separability threshold for Pauli Hamiltonians of bounded degree Δ≥2. If every coefficient in the Hamiltonian has magnitude at most one and each term has overlapping support with at most Δ other terms, the Gibbs state is a mixture of product Pauli eigenstates whenever β≤z_Δ:= arctanh[max_(0≤...)

Proper Agnostic Learning of Matrix Product States and Tree Tensor NetworksTier 3

We establish proper agnostic learning of matrix product states and tree tensor networks. Given copies of an arbitrary quantum state ρ, our algorithms return a state |ψ⟩ of chosen bond dimension such that ⟨ψ| ρ|ψ⟩ is within ε of the optimum over the model class, without assuming that ρ itself belongs to or is well approximated by that cla...

Optimal Two-Qubit Gate-Cutting Cost and Measures of NonlocalityTier 3

Circuit cutting enables quantum computations to be decomposed into smaller subcircuits at the cost of additional sampling overhead. Gate-cutting provides one such approach by replacing nonlocal gates with quasiprobability decompositions of local operations. Starting from the known optimal two-qubit gate-cutting formula, we derive complete sharp lower and upper envelopes rela...

A General Composition Theorem for Approximate DegreeTier 3

A longstanding open question in Boolean function complexity asks whether approximate degree composes multiplicatively under block composition. Although a general multiplicative upper bound is known, matching lower bounds have previously been established only for restricted classes of functions. We resolve this question for all total Boolean functions by proving the matching...

Beyond Bond Gauge: Exact Tensor-Network Tangent Spaces at Weighted Graph StatesTier 3

For normal PEPS, the fundamental theorem settles at the finite level whether virtual-bond gauge exhausts a tensor network's representation freedom. We ask the first-order question at a fixed representation, from both sides of the differential: which tensor variations leave the state unchanged without being bond gauges, and which physical directions can no variation reach? We...

All you need is the universal correlation detector: A unified approach to universalize communication protocols over quantum channelsTier 3

Constructing optimal quantum information protocols without complete knowledge of the underlying states or channels is a central challenge. We address this challenge by developing universal correlation detection as a common building block for quantum communication. Our detectors distinguish a bipartite state from the product of its marginals and attain the same first-order as...

Computational Cryptography from PseudoentanglementTier 3

The advent of pseudoentanglement and computational entanglement theory bootstrapped a wave of research at the intersection of computer science and information theory. In parallel, computational cryptography has undergone substantial development, prompted by the introduction of pseudorandom states and followed by the establishment of a baseline for the computational hardness...

Avoided crossings in spin-boson systems: consequences for adiabatic state preparationTier 3

Avoided crossings in the correlated many-body spectrum play a central role in determining the conditions for adiabatic state preparation in interacting quantum systems. We investigate this connection in finite spin-boson systems by combining exact diagonalization of the many-body spectrum with time-dependent simulations of adiabatic switching protocols. By comparing the adia...

Observation of universal hierarchical relaxation in a quantum simulatorTier 3

Autocorrelation functions play a key role in the theoretical characterization of the dynamical properties of interacting many-body quantum systems. Recently, bringing together the eigenstate thermalization hypothesis and hydrodynamics, it was theoretically predicted that the relaxation of autocorrelators can be described by the \textit{relaxation-overlap inequality}, which,...

Optimal entanglement criteria from trace invariantsTier 3

Randomized measurement protocols give experimental access to low-degree polynomial invariants of a quantum state rather than to the state itself, which raises the question of what the best entanglement criterion is that can be built from finitely many such invariants. In this work we answer this question through convex duality. For each degree we introduce the cone of local...

Quantum heat transport and effects of quantum thermal devices in noncommuting coupled spinsTier 3

Quantum heat transport governs energy exchange processes and statistical laws in non-equilibrium quantum systems, and plays a pivotal role in quantum thermodynamics. We investigate the steady-state thermal transport of a noncommuting coupled spin system. We employ the quantum dressed master equation approach within the framework of open quantum system theory to accurately an...

Evaluating the Effect of the Order of Optimization Passes in Quantum Circuit OptimizationTier 3

Quantum circuit optimization is critical for mitigating the noise inherent in current quantum hardware. Quantum compilers typically sequentially apply multiple optimizations (also called ``optimization passes'') to improve the circuit. The impact of the order in which these passes are executed has yet been largely unexplored. This paper investigates the significance of the o...

Differential hierarchy of the Husimi representationTier 3

Phase-space representations reveal the geometry of quantum mechanics and distinguish quantum features from classical ones. However, the positivity of a density operator is among the properties of quantum states that phase-space representations capture least directly: deciding whether a phase-space function describes a physical quantum state has so far required global conditi...

Anisotropic information geometry of entropy productionTier 3

We reveal that the information geometry of entropy production exhibits an intrinsic anisotropy, providing a unified origin for the inequivalent geometric constraints obeyed by its different components. Using a hierarchical projection structure of quantum relative entropy, we derive an exact orthogonal decomposition of entropy production into three distinct geometric contribu...

Classical Sufficiency in Quantum Statistical ExperimentsTier 3

A quantum measurement transforms a quantum statistical experiment into a classical one, but different measurements generally yield experiments with different statistical information. We introduce quantum-to-classical sufficiency: relative to a prescribed measurement class, a measurement is sufficient if its induced classical experiment Blackwell-dominates those from every ot...

Eigenoperator Entanglement Statistics in Local LindbladiansTier 3

Random matrix spectral statistics are widely used to diagnose quantum chaos in open systems, but whether chaotic eigenvalue correlations are accompanied by Haar-typical eigenoperators remains unclear. We study the operator-entanglement statistics of Liouvillian eigenoperators with near-maximal entanglement, analogous to states near the middle of the spectrum in Hamiltonian s...

Amplified Memory and Finite-Time Regularity in Driven Non-Hermitian SystemsTier 3

We study the roles of broken spectra and exceptional points in finite-time driven non-Hermitian fermionic dynamics. We compute the Nambu biorthogonal correlation matrix for this purpose. The imbalanced-pairing Kitaev chain serves as our concrete realization. Transient passage through a broken-spectrum region amplifies preparation memory. The effect survives when the final Ha...

On the numerical limitations of dual Koopman von Neumann embeddings for solving conservative nonlinear ordinary differential equations on quantum computersTier 3

The simulation of nonlinear ordinary differential equations on quantum computers is inherently challenging, as quantum gates are linear operators on qubit states. In this paper, we put forth a Koopman-von Neumann (KvN) operator based algorithm for solving nonlinear ordinary differential equations on a quantum computer which overcomes the innate limitations of quantum operati...

Exact solution of a boundary-driven transverse-field Ising model with hidden time-reversal symmetryTier 3

The dissipative transverse-field Ising (TFI) model provides a paradigmatic setting for nonequilibrium quantum many-body physics. We show that a class of boundary-driven TFI models subject to dissipation at only one boundary possesses hidden time-reversal symmetry, which enables an exact construction of their nonequilibrium steady states. The solution admits a matrix-product...

QTREX Quantum Reports First Half 2026 Financial ResultsTier 2

Insider Brief PRESS RELEASE — QTREX Quantum Ltd. (Nasdaq: QTEX) (“QTREX” or the “Company”), a company focused on advancing Additively Manufactured Electronics (“AME”) for quantum computing infrastructure, today reported financial results for the six months ended June 30, 2026, and provided a business update. Revenue reached a record...