October 22, 2026

Injection is all you need: parallel universal logic in high-rate concatenated self-dual codesTier 3

We propose a quantum architecture that achieves addressable and parallel universal fault-tolerant logical in high-rate codes. The codes are obtained from the flexible concatenation of small-distance high-rate self-dual CSS codes. Addressable and parallel universal logic on the resulting K logical qubits is injected by fault-tolerantly preparing and then consuming diverse l...

High-fidelity and robust controlled-Z gates for superconducting transmon qubits. I. Intrinsic errors and decoherenceTier 3

Fault-tolerant quantum computing requires quantum gates that combine short duration, high fidelity, and robustness to noise. As quantum processors scale, robustness becomes increasingly important because exhaustive characterization and frequent recalibration of individual gates become impractical. We present a comprehensive optimal-control framework for controlled-Z (CZ) gat...

Alice & Bob Reports Phase 1 Results of France’s PROQCIMA Quantum ProgramTier 2

Alice & Bob has released Phase 1 results for France's PROQCIMA quantum program, detailing technical milestones achieved with their fault-tolerant quantum computing technology. These include operating multi-qubit chips, executing noise-biased CNOT gates, and implementing quantum error correction cycles. The program aims for 1,000 logical qubits by 2032 with an increas...

Previously: 2026-10-13, 2026-10-01

Pure dephasing destroys two-photon amplitude, not nonlinear phaseTier 3

A two-level emitter chirally coupled to a waveguide imprints a π conditional phase on a two-photon pulse, a key component assumed in quantum photonic neural network architectures, but whether it survives the pure dephasing of a solid-state emitter is unknown, since no two-photon scattering treatment includes it. We derive the dephased two-photon amplitude in closed form an...

Meter-scale quantum interconnects between large quantum processorsTier 3

Modular quantum architecture requires long-distance quantum interconnects to stitch together individual processor modules. Such interconnects, long-distance couplers or L-couplers, must support coherent quantum operation over meter-scale distances and scale to multiple connections between any two modules. Here we demonstrate four L-couplers operating between two 120-qubit IB...

From Traveling Waves to Synthetic Gauge Fields: A Field-Free Route to Superconducting Diode EffectTier 3

The superconducting diode effect requires the forward and reverse bias currents to differ, a scenario achieved via inversion and time-reversal symmetries broken together. The latter, and the more crucial one, is inevitably achieved by a magnetic field. Here, we show that a spatio-temporally driven chemical potential of the form, μ_j(t)=μ+Vcos(ωt+kdj), achieves both at o...

Bechtle and IQM Awarded DLR QCI Contract to Supply Superconducting Cloud ResourcesTier 2

Bechtle and IQM Quantum Computers have secured a contract with the German Aerospace Center’s Quantum Computing Initiative (DLR QCI) to provide cloud-based superconducting quantum computing resources until June 2027. This agreement will give DLR QCI researchers access to IQM's quantum processors through the IQM Resonance™ cloud platform, expanding their hardware options fo...

Before the QubitTier 2

How hybrid infrastructure is making quantum commercially actionable today – and why the organizations building that infrastructure now will be the ones ready when the hardware arrives. Insider Brief The Era Between Eras The prevailing assumption about quantum computing is that fault-tolerant hardware will arrive at some point, organizations will integrate it when it does, ...

Resource Analysis of Quantum Optimization Algorithms via Variational MethodsTier 3

Variational Quantum Algorithms (VQAs) are promising approaches for solving combinatorial optimization problems on near-term quantum devices. However, the role played by quantum resources such as entanglement and coherence during the optimization process remains poorly understood. In this work, we investigate the evolution of these resources in two VQAs--the Quantum Approxima...

Mamba Quantum Eigensolver (MQE): A Selective State Space Model for Scalable Ground State Simulations in Quantum ChemistryTier 3

Predicting molecular electronic structure using Quantum Computing approaches is a challenge in Computational Chemistry. Traditional Variational Quantum Eigensolvers (VQEs) are typically hindered by optimization challenges. The alternative Generative Quantum Eigensolver (GQE) mitigates this by reformulating ground-state search as discrete sequence generation, but its Transfor...

Quantum f-divergences from retrodiction: a unifying classical variational principleTier 3

The same classical f-divergence admits inequivalent extensions to quantum states. The question is whether these extensions can be obtained from a common operational variational principle. Here we generalize Matsumoto's reverse-test optimization by introducing a reference prior state. More explicitly, we minimize the statistical distinguishability between a forward and a reve...

Quantum Simulation of Non-Markovian Open Quantum Systems via Low-Rank Kernel Compression and Coupling DilutionTier 3

We present an error-controlled framework for the quantum simulation of non-Markovian open-system dynamics in Gaussian environments. For a system coupled linearly to a Gaussian environment with zero mean, the bath's influence on the reduced dynamics is completely determined by its two-time correlation kernel. This allows us to replace the microscopic environment with an equiv...

Adapted Fröhlich-Pizzo Model for Horizon-Induced DecoherenceTier 3

The Fröhlich-Pizzo (FP) model is a quantum-mechanical model originally developed to describe the interaction between an atom and the electromagnetic field in the nonrelativistic limit c→∞. We show that an adaptation of the FP model based on the local algebras of a U(1) chiral current captures essential features of the horizon-induced decoherence mechanism identifi...

Black Kite Introduces Quantum Readiness Controls to Assess Third-Party Cryptographic RiskTier 2

Black Kite has launched Quantum Readiness, a new feature in its Cyber Rating engine that assesses third-party vendors' preparedness for post-quantum cryptography. This helps organizations identify vendors using quantum-resistant encryption and meet upcoming regulatory deadlines like OMB M-26-15 and EU NIS2. The tool aims to mitigate "harvest now, decrypt later" vulnerabil...

Rutgers And IBM Demonstrate Real-Time Control Across 100 QubitsTier 2

Insider Brief PRESS RELEASE — Researchers from Rutgers, IBM and collaborating institutions have shown that a quantum computer can check what is happening inside it and respond while it is running, repeatedly resetting parts of the system to bring chaotic behavior under control. The advance is a critical step toward building larger, more reliable quantum […]

A random sampling method to test the weak Eigenstate Thermalization HypothesisTier 3

We introduce a random sampling method for testing the weak Eigenstate Thermalization Hypothesis (wETH) that is particularly useful for large, sparse Hamiltonians. We test the method on a well-studied Rydberg atom system that exhibits both two- and three-body dipole-dipole interactions. Our results show that our method allows for the study of system sizes significantly beyond...

An entanglement band structure for general multiqubit statesTier 3

Majorana drew a symmetric multiqubit state as points on the Bloch sphere, antipodal to the zeros of its overlap with spin coherent states. Projecting only one qubit of a general state leaves the others in a state that varies with direction. Its entanglement invariants are eigenvalues of a non-Hermitian matrix and form bands over the sphere. Exceptional points appear, without...

Short qudit triorthogonal codes from doublingTier 3

We construct short triorthogonal codes for qudits of odd prime dimension by generalizing doubling, which combines a triorthogonal code with a code admitting a transversal phase gate, and raises the distance by up to two. This gives codes with parameters [[28,1,4]]_3, [[37,1,5]]_3, [[72,1,6]]_3, [[118,1,8]]_3, [[33,1,5]]_5 and [[20,1,4]]_7, each shorter than the c...

GOTT Funds NPL Project to Scale Trapped-Ion Quantum TechnologyTier 2

Insider Brief PRESS RELEASE — The National Physical Laboratory (NPL) has secured funding through the Government Office for Technology Transfer (GOTT) to accelerate the development of next-generation trapped-ion quantum computing technologies, helping address one of the sector’s most significant barriers to commercial adoption: scalability. Quantum computing has t...

Encoding a bosonic mode into qubits for simulating boson-matter interactionsTier 3

We explore the space-time cost of encoding of a bosonic mode into a set of qubits via various encodings, and their resilience to noise. In particular, we compare the performance of the unary Fock state encoding, an unexplored encoding of Fock states into Dicke states (``Dicke'' encoding), and the binary quadrature encoding. We do so by considering a displacement as well as a...

Geometry-controlled zeros of resonant Kelvin-wave conversion in four spatial dimensionsTier 3

Kelvin waves carry energy along vortices, but their resonant interactions contain information that is absent from the linear spectrum. We identify a geometry that exposes this information on a vortex surface in four spatial dimensions. Perpendicular incoming waves cancel the complete local-area four-wave coupling, leaving the finite nonlocal interaction mediated by the surro...

Buffer-Qubit-Based Quantum Circuit Allocation Method Against Crosstalk AttacksTier 3

Quantum Multi-Programming (QMP) enables the simultaneous execution of quantum circuits from multiple users on a single quantum chip in cloud quantum computing services. However, QMP is vulnerable to crosstalk attacks, in which a malicious user deliberately induces crosstalk to disrupt other users' computations. As a countermeasure, prior work has proposed the use of buffer q...

Pasqal Launches Neutral-Atom Agentic Toolkit and Demonstrates QPU Workflows Across 258 Quantum Physics PapersTier 2

Pasqal has launched an AI-assisted workflow and an open-source Neutral-Atom Agentic Toolkit, enabling the translation of scientific papers and concepts into quantum experiments. This toolkit was validated by reproducing results from 258 arXiv quantum theory papers on Pasqal's QPUs. The software streamlines quantum computing research by automating the engineering pipeline...

Phonon-assisted free-electron recoil control and mechanical sensingTier 3

Mechanical vibrations are fundamental to a wide range of physical phenomena and technologies, yet their ability to actively shape free-electron dynamics remains largely unexplored. Here we theoretically show how an optomechanical membrane provides a phonon-assisted optical interface for controlling free-electron recoil and sensing localized forces. Transverse membrane motion...

The strengthened quantum Hamming bound of Yu, Lai, and OhTier 3

We prove a conjecture of Yu, Lai, and Oh: their rounded family of strengthened quantum Hamming bounds, which interpolates between Hamming-type bounds and the Singleton bound, holds for arbitrary exact quantum subspaces of dimension K>1. The result covers every integer local dimension p≥2, every integer t≥1, both distances 2t+1 and 2t+2, and every interpolation...

Inaccessibility of the Cosmological Singularity to Quantum ProbesTier 3

We propose an operational resolution of the FLRW big bang singularity using quantum probes satisfying a curvature coupled Klein-Gordon equation. Applying the Madelung-Bohm decomposition of a Klein-Gordon field on a classical near-singularity FLRW background, we show that the induced conformal geometry renders curvature invariants finite and makes past directed causal geodesi...

Hydrodynamic description of correlation matrix eigenvalues in a finite temperature expanding free fermionic gasTier 3

A recent work considered the Page curve for entanglement entropy of a freely expanding one-dimensional Fermi gas starting from a finite box (the system) in a zero-temperature initial state that then expands in to a semi-infinite vacuum (the environment). For the case with a single defect at the system-environment junction, it was shown that the Yang-Yang entropy of the syste...

Tight Bounds on the Randomized Communication Complexity of Vector-in-SubspaceTier 3

We prove that the randomized communication complexity of Vector-in-Subspace in R^n with error at most 1/3 is Θ(√n). Alice holds a unit vector u and Bob holds an n/2-dimensional subspace H; they must distinguish u∈H from u∈H^(perp). An exact one-way quantum protocol uses O(log n) qubits, making the problem a geometric example of an exponen...

Two particle interference: The Hanbury Brown Twiss and Hong Ou Mandel experimentsTier 3

I discuss two important quantum optics experiments which depend on two particle interference. In the years since their first demonstration many interesting and instructive variants have appeared, including the use of atoms instead of photons as the interfering particles. This chapter gives a pedagogical overview of some of these results and argues that the two effects are cl...

International atomic clock comparison achieving 5×10^(-18) uncertaintyTier 3

Two single-ion optical clocks, located in the United Kingdom and in Germany, are compared remotely via a 2220\,km long optical fiber link. Both clocks are based on the ^2S_(1/2) (F=0)leftrightarrow^2F_(7/2) (F=3) electric octupole (E3) transition in ^(171)Yb^+. Using more than 10^6 seconds of measurement data, we determine a fractional frequency difference...

Teaching quantum mechanics in secondary schools: A qubit-first learning path to Bell's inequalitiesTier 3

Teaching quantum mechanics at the secondary school level remains a major educational challenge. Traditional historical approaches often present the theory as a sequence of disconnected phenomena, requiring extensive prior knowledge of classical physics before students can appreciate the conceptual structure of quantum physics. In this work, we present the design, implementat...

Conservation in Every Quantum Measurement Outcome?Tier 3

In quantum mechanics, conservation laws are usually understood only statistically and only in the context of unitary evolution: during such evolution, if an observable commutes with the Hamiltonian, its expectation value and Born-rule probability distribution remain unchanged. Individual measurement outcomes, however, disrupt even this weak form of statistical conservation....

Quantum Charge as a Particle/Antiparticle LabelTier 3

We show that the concept of particles and antiparticles is related to the Weyl-Heisenberg group WH_3. Its generators are the position operators x^a, the momentum operators p_a, and the central element Q_(sfv), which defines a subgroup U(1)_(sfv) of WH_3. We show that the wave functions have a charge relative to the group U(1)_(sfv) equal t...

Semiclassical molecular dynamics simulations of electromagnetically induced transparency cooling of 2D and 3D ion crystals in a Penning trapTier 3

Motional modes of trapped-ion crystals in Penning traps can now be cooled to near their ground states via electromagnetically induced transparency (EIT) cooling. Numerical simulations are valuable tools for interpreting EIT cooling results and optimizing experimental protocols, but existing molecular dynamics codes are limited to the simulation of Doppler cooling. In this wo...

Local distinguishability of five quadripartite orthogonal product statesTier 3

The local distinguishability of five bipartite and tripartite orthogonal product states (OPSs) has been effectively resolved, while that of five quadripartite OPSs has not yet been effectively addressed. In this paper, we give the local distinguishability of five quadripartite OPSs, where any two of these five states are orthogonal on exactly one subsystem. Based on the vect...

Accurate Wichmann-Kroll vacuum polarization calculations with Gaussian basis setTier 3

We apply a large Gaussian basis set of size up to N = 500 to calculate the all-order Wichmann-Kroll vacuum polarization correction in highly-charged ion. For a hydrogen-like system, this allows us to obtain an accurate correction value with a level of precision comparable to that of traditional methods. We demonstrate that values of effects that can be calculated as the di...

Quantum-Enhanced Matterwave Interferometry in a Ring WaveguideTier 3

We propose a quantum-enhanced matter-wave interferometry protocol based on fractional-revival dynamics of a Bose-Einstein condensate in a ring, combined with a controlled interaction quench. Using the Truncated Wigner Approximation, we show that nonlinear evolution to the quarter revival generates modest spin squeezing of -2.03±0.28dB, which subsequently degrades under...

A compact ultracold strontium experimentTier 3

We describe a compact and simplified experimental setup for the production of ultracold strontium atoms. Thanks to its low-power oven and coil-free Zeeman slower design, the vacuum system has an overall length of only 40cm including oven, Zeeman slower and all-glass science cell. The oven has a power consumption of 14W at 460°C and produces a collimated flux of 3 10^10at/(s...

Quantum Belief Characterization: A Multi-Shot Notion of EquivalenceTier 3

A recent formulation of quantum belief showed that quantum retrodiction depends not only on the reduced density operator of the system of interest, but also on correlations with a hidden reference system, which leads to the notion of quantum belief equivalence. In this paper we formulate a multi-shot problem, where the extended posterior obtained after one update is used aga...

Photon Correlations Control Quantum Fisher Information in Coherent Multidimensional SpectroscopyTier 3

Coherent multidimensional spectroscopy probes interactions and dynamics of molecular systems through nonlinear optical signals. Quantum light excitation has been explored as a means of controlling these signals, raising the question of how excitation-light correlations affect the precision of molecular parameter estimation from the emitted signal. In this work, we show that...

Bounds on Attainable Rate Modulation in Fermi's Golden RuleTier 3

Controlling transition rates is a central objective across quantum optics, condensed-matter physics, and chemical physics, encompassing processes such as spontaneous emission, energy and charge transfer, spin relaxation, and chemical reactions. Although Fermi's golden rule provides a powerful framework for calculating such rates of weakly coupled transitions, conventional ca...

The Lévy wave packet and fractional uncertainty relationsTier 3

This work revisits the debate on fractional uncertainty relations that arose a decade ago and tries to settle it. After a careful study of the position-momentum uncertainty product of the Lévy wave packet, a novel lower bound is proposed for uncertainty relations in fractional quantum mechanics. This bound is nearly linear in the Lévy index and is satisfied by exact, calcula...

Convergence Analysis of the Quantum Blahut-Arimoto Algorithm and the Contraction Coefficient of Qubit Amplitude-Damping ChannelsTier 3

In this work, we investigate the convergence rate of the quantum Blahut-Arimoto (BA) algorithm proposed for computing the coherent information of less noisy quantum channels. Previous work established exponential convergence under certain restrictive assumptions on the channel. Using a Taylor expansion around a positive definite optimizer, we show that, for an injective degr...

Spin - resolved momentum distributions and vortex evolution in multiphoton pair production within a modified two-level modelTier 3

We investigate spin-resolved momentum distributions and phase vortices in multiphoton electron-positron pair production within a modified two-level model. This model retains the diagonal spinor inner-product terms neglected in the adiabatic approximation, thereby inducing spin-resolved transverse asymmetries in the momentum distribution. For a circularly polarized pulse, the...

Boundary exceptional point driven chiral switch of topological edge statesTier 3

We theoretically investigate the interplay of topology and localized non-Hermiticity in a finite Su-Schrieffer-Heeger chain characterized by non-Hermitian potentials at its boundaries. By tuning the boundary gain and loss parameters, we exploit the finite-size hybridization of two mid-gap topological edge states to analytically derive the exact coordinates of boundary-induce...

Low-field dephasing time of an optically polarized NV^- spin bath beyond the P1 limit in diamond: a cluster-correlation-expansion and exact spin-bath studyTier 3

Dense ensembles of nitrogen-vacancy (NV^-) centres in nitrogen-rich diamond dephase on the electron spins of the substitutional nitrogen (P1) centres. If the paramagnetic nitrogen is instead converted into NV^- centres, the laser that initializes the sensor also pumps the bath into m_s = 0, a state with no moment along its own axis. Using cluster-correlation-expansion...

PQ-Vault: Provably Quantum-Safe Asset Custody for Unmodified EthereumTier 3

A quantum computer could recover the key of any Ethereum account whose public key appears on chain. We prove that no sidechain or bridge that leaves Ethereum's rules unchanged can protect such accounts: their funds must move into a contract whose release condition relies only on quantum-safe primitives. We design \emph{PQ-Vault}, a custody system for unmodified Ethereum comb...

Alignment of the amplitudes of stored states for solving the associative memory problem using quantum annealingTier 3

The solution of combinatorial optimization problems by means of quantum annealing is based on the preparation of an equally superposition state. Such superposition is crucial to the associative memory problem of correctly recalling patterns. In this paper, we study the alignment of the amplitudes of stored states in memory using the proposed auxiliary Hamiltonian, which is s...

Readout Dependent Parameter Identifiability of Quantum KernelsTier 3

A circuit parameter can change measured features without changing their projected Gaussian kernel. We characterize this lost dependence and distinguish recovery by metric design from nonlinear feature expansion. With analytic feature coefficients, a fixed finite data basis affinely independent on the input domain, a fixed positive definite metric, and fixed bandwidth, the co...

Turning Quantum Compiler Configuration Selection Upside Down: A Top-Down ParadigmTier 3

Selecting an effective quantum compiler configuration requires coordinated decisions over both hardware targets and compiler settings, with the ultimate goal of improving circuit execution fidelity. Existing SOTA approaches typically decompose this problem into two sequential stages: a device is chosen first, after which compiler options are tuned on that device through RL-b...

Evaluation of the quantum Fisher information for large systems via an ancillaTier 3

Quantum Fisher information (QFI) is a fundamental quantity in quantum information and quantum mechanics, and evaluating it in various physical systems has become an important research topic. However, its evaluation in large systems still faces many challenges. Hereby we propose an ancilla-based protocol for evaluating the QFI of large systems and establish the conditions und...

Fast Template Matching for Quantum Circuits Using HypergraphTier 3

Quantum circuit optimization is a key step toward the efficient execution of quantum algorithms. Template matching has emerged as one of the dominant approaches for simplifying quantum circuits, yet it confronts the intrinsic challenge of accommodating gate commutativity. The state-of-the-art template-matching algorithm relies on a directed acyclic graph (DAG) representation...

Algebraic criteria for complete relaxation in autonomous and periodically driven open quantum systemsTier 3

We derive sufficient criteria that guarantee convergence of open quantum system dynamics to a unique long-time state independent of the initial conditions. We refer to this behavior as complete relaxation. Focusing on systems described by Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) master equations on finite-dimensional Hilbert spaces, our approach uses only elementary math...

QUBO-Based Conformer Selection with Quantum-Classical Hybrid Optimization for Multiconformer Ligand ModelingTier 3

A ligand can adopt multiple conformations within the same binding site, and these conformations can interact differently with the surrounding protein. Multiconformer modeling must therefore determine which candidate conformations to retain and what occupancies to assign to them. An established automated approach uses mixed-integer quadratic programming (MIQP) with hard occup...

Plurilock Files Information Circular and Schedules Shareholder Vote for C$33.8M ($24M USD) Acquisition by Quantum eMotionTier 2

Plurilock Security Inc. will hold a shareholder meeting on November 18, 2026, to vote on its acquisition by Quantum eMotion Corp. for C$33.8 million (~$24 million USD). Plurilock shareholders will receive C$0.084 in cash and 0.0763 of a Quantum eMotion common share for each Plurilock share. This acquisition aims to integrate Quantum eMotion's quantum random number generat...

Plurilock Sets Vote on Quantum eMotion AcquisitionTier 2

Insider Brief Plurilock Security shareholders will vote Nov. 18 on a proposed acquisition by Quantum eMotion, a deal intended to pair quantum-based security technology with an established cybersecurity business and its customer network. Plurilock said in a news release that it has filed and mailed documents explaining the transaction ahead of a special shareholder meeting ...

URI Students Teach Quantum Computing at Brookhaven National LaboratoryTier 2

Insider Brief PRESS RELEASE — As a sophomore at the University of Rhode Island three years ago, Morgan Beck ’26 began diving deep into the world of quantum physics, wanting to learn more about the branch of science that studies matter and energy at the most fundamental level. At that time, Beck—a 2025 URI College […]

Study: AI Could Speed Quantum Threats — And Help Build DefensesTier 2

Insider Brief Artificial intelligence could hasten quantum attacks on encryption while helping organizations prepare for them, according to a new analysis that calls for treating the technologies as a single cybersecurity challenge. The paper, published in the Journal of Quantum Information Science by Troy Coienth Troublefield, of Capitol Technology University, proposes that...

Splitting Probability in Monitored Quantum DynamicsTier 3

We consider a continuous-time quantum walk stroboscopically subjected to projective measurements on two distinct targets with sampling time period τ. We construct a general renewal framework for the first-detection amplitude at each target, from which we obtain the associated splitting probabilities. For Hamiltonians with reflection symmetry, we further show that each dual...