September 2, 2026

Fast Microwave-free State Preparation and Measurement of Superconducting QubitsTier 3

Fast, high-fidelity, scalable state preparation and measurement is critical to the realization of a quantum computing system. The state-of-the-art methods for preparation and readout of superconducting qubits require finely tuned microwave signals and ~100 ns of measurement time, which are major obstacles to the scalability and performance of superconducting quantum computer...

A Scalable Multi-Protocol Platform for Quantum Key Distribution Simulation with Rigorous Statistical EvaluationTier 3

Quantum Key Distribution (QKD) offers information- theoretically secure key establishment grounded in the laws of quantum physics, yet its practical reach is limited by the prohibitive cost of photonic hardware and the fragmented nature of existing simulation tools. Most simulators support only a single protocol and report results from individual stochastic runs, making syst...

Exceptional Points in Photonics: From Non-Hermitian Physics to ApplicationsTier 3

Open photonic systems provide a versatile platform for non-Hermitian physics, enabling control over complex spectra, transport, and light-matter interactions. Exceptional points (EPs), at which eigenvalues and eigenvectors coalesce and the governing operator becomes defective, play a central role because they combine branch-point spectral topology, nonanalytic perturbative r...

Photonic fusion operations transform partial distinguishabilityTier 3

Photonic fusion operations are a central primitive in photonic quantum information processing and are commonly characterized by their success probability and resource cost. Here, we identify an additional way in which different implementations of fusion operations differ, namely in how they transform partial distinguishability. We consider distinguishability originating both...

Robust CZ gate against flux line memoryTier 3

High-fidelity CZ gates are central to superconducting quantum processors, but implementations based on flux tuning are still sensitive to pulse distortion. Conventional predistortion, typically used for an isolated gate, can recover the desired flux at the chip but it fails if the flux line memory exists, causing the fidelity of repeated CZ gates to drop rapidly. To address...

Structure-Aware Placement and Routing of Multi-Controlled Toffoli on Bivariate Bicycle Code ArchitecturesTier 3

The multi-controlled Toffoli (MCT) gate is a fundamental primitive in quantum circuit design, with applications in quantum arithmetic, cryptanalysis, and algorithmic implementations. Being a high-level logical operation, the efficient decomposition of MCT gates into lower-level netlists has remained a major optimization challenge for decades. While emerging quantum error-cor...

High-Rank Encoding Can Improve Approximate Quantum Error CorrectionTier 3

Conventional quantum-code constructions encode pure logical states as pure code states, but this restriction can sacrifice performance. We show that intrinsic encoding randomness can improve optimal entanglement fidelity. We bound the loss from imposing a rank-one encoder and prove it is at most quadratic near perfect recovery after joint optimization. The optimized advantag...

Superconducting Flux Memory for Cryogenic ApplicationsTier 3

We report the development of flux memory for use with superconducting circuits. This technology stores persistent currents in superconducting loops on-chip to be used to provide flux biasing for superconducting circuits, like qubits. We developed three types of flux memory and draw comparisons among them for circuit design. We demonstrate the utility of flux memory by using...

Completing or Refusing Low-Dimensional Records of Structured Quantum Circuits: Measurement Loss, Compression Loss, and Hardware DriftTier 3

Structured quantum circuits are often summarized by low-dimensional records. Records lose control-dependent information when they merge outcomes whose probabilities respond differently to circuit parameters. We assess this loss without a parametric hardware-noise model or low-dimensional statistical family. Quantum Fisher information bounds premeasurement sensitivity; Fisher...

Previously: 2026-07-07, 2026-06-21, 2026-06-15

Unbiased sampling from Boltzmann distributions with noisy energiesTier 3

Sampling from the Boltzmann distribution is central to computational physics, yet hard when the energy is known only through a stochastic estimate, such as with machine-learned molecular potentials, in variational Monte Carlo, or on quantum computers, because a noisy energy biases the sampled distribution. The penalty method of Ceperley and Dewing corrects this but requires...

QILP-0: Constructing Observational Declarative Twins of Quantum CircuitsTier 3

This paper introduces QXymb, a general framework for constructing observational declarative twins of quantum circuits, and develops QILP-0, its first complete order-0 specialization. QILP-0 constructs a finite multi-valued propositional logic program from observed circuit behaviour within a declared observational scope. The pipeline traverses a declared family of quantum obs...

A hybrid quantum-classical neural network for learning to routeTier 3

This work studies hybrid quantum-classical neural networks for learning routing heuristics. Specifically, this paper asks whether small quantum neural networks can replace parameter-heavy modules inside a competitive attention-based routing model while maintaining solution quality. For the capacitated vehicle routing problem, encoder feed-forward replacement emerges as the m...

A Backend-Agnostic MWIS Kernel for Stochastic Unit Commitment with Neutral-Atom Hardware ValidationTier 3

Quantum hardware is beginning to address structured combinatorial optimisation, but two steps still block practical use: mapping real operational models onto hardware-compatible instances, and converting noisy hardware output back into feasible decisions. Here we introduce a backend-agnostic computational interface that compiles the discrete decision layer of stochastic unit...

Quantum-Based Optimization of Gas Throughput in Natural Gas Transmission Networks Under Hydraulic Constraints Using QAOATier 3

Maximizing gas throughput in transmission networks under hydraulic and operational constraints is a combinatorial problem whose complexity grows exponentially with network size, making it computationally intensive to solve exactly. This paper addresses the graph-based optimization problem by optimizing nodal-pressure assignments under the Panhandle-B hydraulic equation. By f...

Symmatrics Launches AI and Post-Quantum Readiness PledgeTier 2

QC Ware and IonQ Demonstrate Hybrid Quantum Chemistry Workflow for Drug DiscoveryTier 2

The Quantum Insider Launches TQI 2.0, A Comprehensive Intelligence Workspace For The Quantum EconomyTier 2

MIT Quantum Initiative Launches Postdoctoral Fellowship ProgramTier 2

Diraq to Deploy a Quantum Computer Inside an Equinix Data CenterTier 2

Previously: 2026-09-01

Observable- and state-selective prethermalization and bounds on prethermal lifetimesTier 3

Prethermalization describes long-lived intermediate regimes that precede equilibrium and can dominate experimentally accessible dynamics. Here, we show that a separation of spectral energy scales, despite giving rise to a hierarchy of dynamical timescales, does not by itself guarantee the appearance of a prethermal plateau. Under the same Hamiltonian, some observables may ex...

Depth-1 expanders on the unitary group and applicationsTier 3

We construct a constant-degree and constant-gap quantum expander on n qubits where each unitary can be implemented by a depth-$1$ and 1D circuit of Pauli or CNOT gates. We provide two applications of this expander. First, we use it to construct a family of frustration-free 1D Hamiltonians whose ground states obey the entanglement-gap relation S = Θ(Δ^(-1/2)); this is bel...

Quantum Weighted Moving Average for Predicting Limit Order Book TrendsTier 3

Can quantum computers be useful for forecasting multivariate financial time series? In this work, we consider the problem of predicting price trends from limit order book (LOB) data. After identifying key components of classical models, we introduce the quantum weighted moving average (QWMA) model. The two main building blocks are, first, classically preprocessing via normal...

Behavioral Memory under Symmetry in One-Way Quantum AutomataTier 3

Under compact symmetry, observable behavior reduces to an invariant operator algebra, but its dimension is not yet classical memory: some coordinates are dynamically frozen, some invisible to threshold tests, and some already classical. We develop an operator-algebraic theory that separates these effects through three filters. For one automaton, behavior is the Hilbert--Schm...

Verifiable quantum advantage in extremely low depthTier 3

We give a sampling problem that is solvable by shallow quantum circuits, hard for polynomial-time classical algorithms under lattice-based assumptions, and efficiently verifiable by a classical computer. The quantum sampler admits two implementations: one uses log-logarithmic-depth quantum circuits with one- and two-qubit gates, i.e., QNC^0[loglog] circuits, whi...

Exact Virtual Channel Programming with Vanishing Excess OverheadTier 3

A finite-dimensional physical processor cannot exactly program a continuous family of distinct unitary channels. We show that this obstruction becomes quantitative when the target channel is stored in a normalized Choi state and its output observables are reconstructed by sampling physical channels and classically post-processing their measurement outcomes. For arbitrary d...

Local Gaussian bounds on the non-destructive discrimination of two-mode squeezed statesTier 3

Typical measurement setups in quantum systems are destructive, meaning that states are irretrievably altered after measurement. In this work, we analyse non-destructive discrimination of two two-mode squeezed vacuum states using local Gaussian measurements. We investigate a tradeoff relation between the success probability of discrimination and the fidelity of the resulting...

Quantum phase transitions of the Cavity Heisenberg spin-chainTier 3

The interplay between quantum criticality and ergodicity breaking constitutes a central challenge in complex quantum many-body systems. Here, we investigate ground-state quantum phase transitions (QPTs) and excited-state quantum phase transitions (ESQPTs), as well as ergodic-nonergodic transition in the cavity Heisenberg spin-chain (CHS) model. By combining quantum informati...

Dynamical regimes of QAOA gradient responseTier 3

Characterizing the trainability of the Quantum Approximate Optimization Algorithm (QAOA) requires understanding how its gradient landscape changes across circuit parameters and problem size. Yet these gradients are usually described in terms of the native QAOA angles, making it difficult to distinguish parameter specific features from broader changes in the underlying circui...

A nonabelian anyon violates Haag dualityTier 3

We show that a superselction sector describing a single nonabelian anyon violates Haag duality, which is equivalent to the fundamental quantum-information theoretic principle of uniqueness of purifications. We provide a simple physics argument as well as a rigorous proof using sector theory, and instantiate our result concretely in Levin-Wen models. We also show that the ass...

DF-SQD: Deterministic Fields for Sampling-Based Quantum DiagonalizationTier 3

Sampling-based quantum diagonalization method exploits Quantum-centric supercomputing platforms to sample bitstrings for Hamiltonian projection on a quantum computer, and then classically diagonalize the Hamiltonian to estimate the eigenvalues and eigenvectors. In current quantum devices an algorithm is useful when shallow quantum circuits with error mitigation support can d...

Dynamical phase transitions for single particles in the semiclassical and weak noise limitsTier 3

We present a unifying description of dynamical phase transitions in the unitary evolution of an isolated quantum particle and the dissipative relaxation of a classical Brownian particle, based on a dynamical generat- ing function. In the semiclassical and weak-noise limits, Fisher zeros of this function condense in the complex- time plane and reach the corresponding physical...

Quantum time-flip beats adaptive metrology: Asymptotic benefit, activation, and unsimulabilityTier 3

In quantum metrology, adaptive and causal-superposition strategies are proven to be beneficial over parallel schemes for a finite number of channel uses, but their advantages disappear in the asymptotic limit. We show that quantum operations with indefinite time direction, specifically, time-flip (TF)-assisted strategies, referred to as indefinite time-directed metrology (IT...

A continuous-mode quantum-optical representation of finite strong-field laser pulses in free spaceTier 3

We formulate an energy-consistent quantum-optical representation of finite paraxial laser pulses in free space. The formulation is based on a continuous-mode description and provides a step toward a unified treatment of coherent and nonclassical strong-field drivers. Starting from plane-wave quantization, we construct a transverse vector-mode reduction in which the selected...

Direct laser-written optomechanical double membranes in an optical microcavityTier 3

Optomechanical membrane-in-the-middle systems that comprise several coupled compliant membranes offer enhanced optomechanical coupling and collective dynamics. Recent realizations were fundamentally restricted to two membranes and to limited structural optimization of the involved membranes due to their intricate fabrication and experimental integration. Here, we present a f...

Scattering and Tunneling in Real Quantum MechanicsTier 3

We establish the general form of the evolution equation and study scattering and tunneling in real quantum mechanics. We prove an analogue of Stone's theorem for a real Kahler space and derive the corresponding general evolution equation, whose evolution operator is both orthogonal and symplectic. We formulate scattering theory in terms of real wave operators and the associa...

Colored-Noise-Induced Horizon Fluctuations Near a Double Root in an Effective Black-Hole GeometryTier 3

Stress-tensor fluctuations carry information that is absent from the mean semiclassical Einstein equation, but their observable effect depends as much on the response of the geometry as on the noise itself. We formulate an effective, quasistationary spherical model organized by the response--noise structure of a quantum Langevin equation. A prescribed mean dressing and a hor...

Tangent fermions can restore vacuum stability of discrete-time Dirac modelsTier 3

The Dirac quantum walk (a 1+1 dimensional space-time discretization of the Dirac equation) has a 2μ mass gap both at the center and at the corner of the quasi-energy-momentum Brillouin zone. Gupta and Short recently noted [Quantum 9, 1845 (2025)] that the Dirac vacuum can create a particle-hole pair at the zone corner with the release of an energy 2μ to the environment....

Nonlocal wavefront shaping through complex mediaTier 3

Wavefront shaping is a key technique for mitigating scattering in complex media, enabling advanced imaging and optical communication. Yet existing approaches are inherently local, requiring active correction elements - such as spatial light modulators or deformable mirrors - to lie directly in the optical path of the scattered light, which limits their integration into compa...

Uniform Hiding of Haar Block Transpose Gram MatricesTier 3

Gaussian boson sampling with equally squeezed active inputs assigns collision free probabilities through a complex symmetric transpose Gram matrix formed from a rectangular block of a Haar interferometer. We prove a finite total variation comparison with the corresponding complex Gaussian transpose Gram law. The error bound is explicit, quadratic in the number of selected ou...

Information geometry of non-equilibrium quantum states: Mixed metric structures on an extended information manifoldTier 3

We discuss an information-geometric framework for characterizing quantum states in non-equilibrium dynamics. Using the transverse-field Ising chain model as a laboratory, we investigate the quantum Fisher information metric with particular emphasis on the mixed metric component g_(ht) and related geometric observables, where h is a controllable post-quench Hamiltonian pa...

Topological charges and parity selection at Floquet quasienergy degeneraciesTier 3

The quasienergy spectrum of a strongly driven two-level system as a function of the driving parameters exhibits conical intersections, which are enabled by hidden time-nonlocal symmetries. We show that each such crossing carries a quantized topological charge: the Floquet--Berry phase acquired along an adiabatic loop around a cone is equal to a Z_2-valued charge....

Kibble--Zurek Mechanism and Defect Freezing in Imbalanced-Pairing Kitaev ModelsTier 3

We investigate driven dynamics across critical and exceptional points in the one- and two-dimensional imbalanced-pairing Kitaev models using both the wave-function normalization approach and the biorthogonal framework. For a positive pairing imbalance parameter, the quasiparticle spectrum remains real, and a pairing imbalance neither shifts the equilibrium phase boundaries n...

Thermal screening and critical scaling of quantum energy teleportation in a harmonic chainTier 3

We develop a finite-temperature Gaussian-state formulation of quantum energy teleportation in the one-dimensional harmonic chain. For Gibbs states, the optimized measurement-feedback protocol reduces to thermal two-point functions. In the single-site protocol, the extracted energy is governed by a single correlator, which makes the thermodynamic and near-critical limits anal...

Towards Natural Gas Contract Selection via Quantum-Guided Independent Set ReductionTier 3

Selecting mutually compatible natural gas transportation contracts is a practically important optimization task in which operators must choose from many candidate agreements subject to temporal, infrastructural, and flow-related constraints. As the number of candidates grows, the resulting search space becomes difficult to explore exhaustively. We study a pairwise abstractio...

Understanding IR singularities in the Loop-Tree DualityTier 3

One of the main advantages of the Loop-Tree Duality representation of scattering amplitudes is that it makes the origin of infrared and threshold singularities particularly transparent. This talk reviews recent progress in describing how singularities emerge and cancel at the level of scattering and vacuum amplitudes, discusses a novel strategy to efficiently construct finit...

Ontic and epistemic states in the theory of spacetime-local beablesTier 3

Bell's theorem rules out developing a locally causal theory to describe quantum phenomena. Many take this to imply that any model of quantum entanglement must employ variables (called beables by Bell) which follow nonlocal rules, even though signaling is local. The alternative is to adopt an all-at-once (block universe) approach, with beables which may depend on both past an...

The Fermionic Cohomology Problem on the Full Fock Space Is QMA_1-CompleteTier 3

Fermionic cohomology characterizes the zero-energy states of the supersymmetric Hamiltonian associated with a fermionic differential. Previous work showed that the problem restricted to a particle-number sector specified with the input is QMA_1-hard and belongs to QMA. We study the global problem, in which no sector is specified and cohomology may occur...

Parametric amplification of continuous-variable entangled state for loss-tolerant quantum distributed sensingTier 3

Quantum metrology exploits quantum states to achieve an estimation sensitivity beyond classical limits. In the continuous-variable (CV) regime, the squeezed state has been used to implement deterministic quantum sensing, but the quantum metrology sensitivity of this state is significantly affected by losses or detection inefficiencies, which restrict its applications. In thi...

Separating perception from reasoning in vision-language models: a model-free render ceiling for crystal structuresTier 3

Multimodal evaluations cannot say whether a vision-language model misread an image or misreasoned about it, because every existing method for separating the two places a second model in the loop. We introduce the render ceiling, a model-free reference for benchmarks built by rendering known objects: inverting the frozen cameras and re-solving cross-view correspondence recove...

Feedback-Enhanced Quantum Metrology and Clock Precision under Thermodynamic UncertaintyTier 3

Feedback can convert continuously monitored quantum jumps into a thermodynamic resource. We formulate full counting statistics for open quantum systems under unital jump feedback by incorporating the feedback maps into the tilted generator. The resulting trajectory ensemble determines both current fluctuations and the Fisher information of the measurement record. We show tha...

Parafermions in plain sightTier 3

We show that for any potential with a discrete energy spectrum, the well-known interpolation between ideal boson and fermion partition functions at discrete values of ξ=-1/m yielded zero temperature ground state energies corresponding to m fermions occupying a single quantum state. The grand canonical partition function in this case can be a result from genuine parastati...

Imaginarity witnessing enhancement via spectral norms of witnessesTier 3

Quantum imaginarity is an essential physical resource that underpins key functionalities of modern quantum technologies. We improve imaginarity witnessing via the prior knowledge of imaginarity-witness operators. To this end, we derive a rigorous upper bound on the maximum expectation value of an imaginarity witness operator over the set of all free (real) quantum states, wh...

Arqit, Es’hailSat and AIEE Demonstrate Quantum-Safe Satellite CommunicationsTier 2

Emerging Personas and Tools for Hybrid Quantum-HPC SystemsTier 3

Quantum computing is entering an era where quantum processing units (QPUs) with tens to hundreds of qubits are increasingly integrated with high-performance computing (HPC) systems to support hybrid quantum-classical workloads. This paradigm, often referred to as Quantum-Centric SuperComputing (QCSC), introduces new operational, software, and infrastructure challenges. In th...