October 27, 2026

A Control Line Multiplexing Framework for Scalable Quantum ComputingTier 3

Universal fault-tolerant superconducting quantum computers are expected to require millions of physical qubits; yet extending the prevailing dedicated-control-line paradigm to this scale would exceed the wiring density and cooling-power budget of dilution refrigerators. Microwave frequency-division multiplexing (FDM) revolutionized classical communications by enabling many i...

Decoding with alternating weighted graph sparsification for quantum low-density parity-check codesTier 3

Real-time decoding is a fundamental necessity for building fault-tolerant quantum computers. In this work, we introduce decoding with alternating weighted graph sparsification (DAWG), an ensemble based approach that combines Tanner graph sparsification with ensembling belief-propagation (BP) decoders. The DAWG decoder runs BP decoders over the full detector error model Tanne...

Growth Phase Map of α and \b{eta} Tantalum as a Function of Growth Temperature and Oxygen Partial PressureTier 3

Tantalum thin films are used in low-loss superconducting quantum circuits, yet the growth conditions governing selection of α-Ta(110), α-Ta(111), and metastable β-Ta on c-plane sapphire remain uncertain. We deposited 100 nm Ta films by dc magnetron sputtering on Al_2O_3(0001) at 300-900 ^∘C while varying the O_2 partial pressure from a 5.5×10^(-11) T...

Multimode continuous-variable quantum key distribution with CMOS-compatible photonic-electronic integrationTier 3

Multiplexing and photonic-electronic integration offer a route to scalable and high-throughput quantum key distribution (QKD) networks through parallel transmission and compact hardware suited to volume manufacturing. Realizing this route requires multichannel transmitters and receivers, and a security analysis accounting for mode coupling. Here we present a CMOS-compatible...

Interference-induced dynamical crossovers in quantum walks on disordered square latticesTier 3

We study discrete-time quantum walks with Fourier, Grover, and Hadamard coin operators on disordered square lattices, alongside classical random walks. Edges in the lattice are absent with a probability, p. In this case, both classical and quantum walks exhibit an essentially identical degradation of transport. We then study a general version of this model, in which the ex...

Self-Correcting 3D Surface Code with Growing Local DimensionTier 3

We construct self-correcting 3D surface codes over Z_q with local dimension q growing with system size. The model preserves the local geometry and stabilizer support of the ordinary 3D surface code and remains translation invariant in the bulk, while modifying only the stabilizer Pauli powers. We use the Lee metric to characterize error weight and consider local...

Spectral fingerprint recognition of mobile signals via Rydberg atomic sensorsTier 3

Rydberg-atom sensors have emerged as a promising quantum technology for broadband radio-frequency detection owing to their intrinsic calibration, wide frequency coverage, and high sensitivity. However, their potential for intelligent identification of real-world wireless signals remains largely unexplored. Here, we demonstrate a quantum-enabled framework for mobile signal cl...

From Single Spins to Ensembles: A Calibrated Symbolic Regression Pipeline for NV SpectroscopyTier 3

Characterizing nitrogen-vacancy (NV) ensembles requires connecting their collective spectra to individual centers that experience different local environments. We develop a symbolic-regression pipeline that carries single-center spin structure into a calibrated ensemble model by generating individual spectral responses and combining them with explicit weights. A constrained...

The ε-smoothed Entanglement of Formation and its relation to the Moreau-Yosida approximationTier 3

We describe a family of convex continuous functions E_(F,ε), ε∈(0,1], on the set of states of a bipartite quantum system (consisting of finite-dimensional or infinite-dimensional subsystems) obtained by applying the Mora-Piani-Briegel construction of ε-measure (proposed in [Phys. Rev. A 109, 052413]) to the Entanglement of Formation (EoF...

Twist-controlled imaginary-time Mpemba effect in quantum spin systemsTier 3

We construct a controllable imaginary-time Mpemba effect in quantum spin systems using spatially modulated local rotations without changing initial bipartite entanglement spectra and correlation magnitudes. This feature unambiguously isolates the redistribution of spectral weights as the sole driver of the anomalous relaxation. Using the compact-boson description, we reveal...

Equilibrium propagation in non-equilibrium quantum systemsTier 3

Equilibrium propagation (EP) is a powerful training algorithm for self-learning physical systems that is widely used for a variety of machine learning inspired tasks. It relies on the existence of an energy function that depends on tunable training parameters, and can be extended to apply to many-body quantum systems in equilibrium. A key challenge however is the need to rep...

Photometric Redshift Estimation with Hybrid Quantum Neural NetworkTier 3

A Hybrid Quantum Neural Network (HQNN) is applied to recover the photometric redshift of a galaxy dataset built using data from two astronomical surveys, the Kilo-Degree Survey (KIDS) and the VISTA Kilo-Degree Infrared Galaxy (VIKING), which provide data with coverage from the optical to the near-infrared electromagnetic spectrum. The results are then compared with those obt...

Comparing classical and quantum QUBO solvers: optimality, trajectory diagnostics, and limits of solver selectionTier 3

Comparing solvers for quadratic unconstrained binary optimization (QUBO) requires distinguishing solution quality from optimality certification. We compare classical, tensor-network, and fixed-schedule quantum approaches on 180 benchmark instances from ten families with 14-48 variables, supplemented by harder synthetic instances with known optimal solutions, extending to 128...

IDEMIA and KT Deploy Quantum-Resistant SIMs Supporting Dual NIST and KpqC Algorithms for South Korean Military NetworksTier 2

IDEMIA Secure Transactions and KT Corporation are deploying quantum-resistant SIMs in South Korea's military networks, supporting both NIST and Korean Post-Quantum Cryptography (KpqC) algorithms. This initiative, part of South Korea's 2026 Post-Quantum Cryptography Pilot Conversion Project, aims to enhance crypto-agility and secure military communications against future q...

Previously: 2026-10-24, 2026-08-27, 2026-08-27

Electron-photon entanglement in real space from quantum electrodynamicsTier 3

We study the entanglement between an electron and the photon it scatters, resolved in real space and time. Starting from nonrelativistic QED in Fermi's oscillator representation, we write Fock's coupled equations for components with fixed photon number in the photon configuration space, in the length gauge, where the photon is created around the atom through a nonlocal kerne...

Quantum computation of energy level degeneracy and thermodynamical properties of spin systemsTier 3

We propose a hybrid quantum-classical method for reconstructing energy-level degeneracies and thermodynamic properties of spin systems. A single ancilla qubit is used to measure the partition function at imaginary inverse temperatures. For spectra lying on a known equally spaced energy grid, the inverse discrete Fourier transform allows exact reconstruction of degeneracies i...

Quantum-Classical Framework for the Joint Optimization of Bidirectional EV Charging and Trip AssignmentTier 3

The integration of bidirectional (V2G) charging allows electric vehicle (EV) fleets to operate as distributed energy assets. However, the joint optimization of charging schedules and trip assignments is NP-hard. Moreover, bidirectional power flows create non-monotonic state-of-charge (SoC) dynamics that weaken standard dual-based Benders cuts. We propose a hybrid quantum-cla...

Report: UK’s £30 Million Quantum Testbed Program Helps Suppliers Advance Toward Commercial DeploymentTier 2

Insider Brief Britain’s £30 million quantum computing testbed program helped seven hardware suppliers develop systems for use outside their own laboratories, offering lessons in installation, reliability and customer support as the country begins a broader evaluation of the machines, according to a new report. The National Quantum Computing Centre’s Phase 1 report, released...

Network nonlocality with tripartite entangled sourcesTier 3

Quantum networks are built from independent sources, and their nonlocality has mostly been studied with sources that emit bipartite entangled states. A source of three entangled qubits is richer, since its nonlocality can be tested by the Mermin or the more demanding Svetlichny inequality. We ask how network nonlocality relates to these two single-source notions and find tha...

Complete entropy contraction from conditional hyperboundednessTier 3

For finite-dimensional quantum channels compatible with a faithful conditional expectation, we show that conditional hyperboundedness and strict GNS contraction together yield a relative entropy contraction. For KMS-symmetric quantum Markov semigroups, a conditional 2→q hyperboundedness at time t_0>0 combined with a GNS gap λ>0 implies a modified logarithmic Sobolev...

Sparse Carleman Embeddings for Nonlinear Discrete Dynamical SystemsTier 3

Discrete nonlinear dynamical systems arise in population models, iterative optimization, and numerical simulations, where computing many iterations can be costly in high dimensions. We study Carleman embedding for forced quadratic discrete systems and its application to quantum state preparation. Under explicit stability and initial-state assumptions, we prove that the trunc...

Compositional Operational Rank, Smooth Realizability, and Dimensional ReductionTier 3

Higher-dimensional theories distinguish the dimensionality of a microscopic description from the number of directions accessible to a physical observer. Relating these notions requires not only dimensional reduction, but also a consistent preservation of operational independence across different levels of description. We establish sufficient conditions under which a composit...

Competing coherence geometries in positive maps: positivity hierarchies, atomicity, and optimal entanglement witnessesTier 3

We introduce a family of positive maps on qudits whose Choi operators combine two competing coherence patterns: independent exchange couplings and a collective set of diagonal couplings. For every mixed member of the family, we derive exact conditions for positivity, complete positivity, and all intermediate levels of k-positivity, and we determine the complete phase structu...

Parametrically Enhanced Ergotropy and Charging Power in a Three-Mode Bosonic Quantum BatteryTier 3

Quantum batteries are quantum systems that potentially serve as fuel for other quantum devices by receiving and supplying energy. In this work, we propose a theoretical scheme to enhance ergotropy and charging power of quantum Battery in the system under consideration through squeezed light. Moreover, The system comprises a coherently driven charger cavity, a strongly dissip...

Distillable entanglement is continuousTier 3

We prove continuity of distillable entanglement, the optimal asymptotic rate at which copies of a bipartite state can be converted into maximally entangled pairs by local operations and classical communication (LOCC) with vanishing error. We establish an explicit asymptotic continuity bound that holds for arbitrary bipartite states and depends logarithmically on the system d...

Bell-pair distillation under imperfect operationsTier 3

We recently proposed an entanglement distillation protocol based on local operations and classical communication that probabilistically and universally distills a maximally entangled Bell pair from multiple copies of an unknown two-qubit state [Phys. Rev. Lett. 135, 260202 (2025)]. Here, we investigate the robustness of this protocol against imperfections in its implementati...

Quantum-Inspired and Optimization-Based CT Reconstruction Through Spin-ErrorTier 3

Quantum-optimization-based computed tomography (CT) reconstruction has demonstrated quantum supremacy in reconstruction accuracy over conventional classical methods under sparse-view and corrupted-sinogram conditions. However, scaling this approach remains challenging because larger images require increasingly many binary variables and interactions in the underlying quadrati...

Quantum-enhanced metrology with classical shadowsTier 3

Quantum metrology relies on observables that maximize information about the parameter of interest, but are often hard to access. We develop a protocol that combines Pauli moments estimated from a fixed ensemble of randomized local measurements into an optimized method-of-moments estimator. For local Pauli classical shadows, we derive the shadow information which determines e...

Did the Gran Sasso Experiment Rule Out the Diósi-Penrose Theory? Musing on the 2021 Result and the Present Experimental StatusTier 3

In 2021, a low-background experiment at the Gran Sasso National Laboratory searched for spontaneous radiation predicted by the standard Markovian Diósi-Penrose (DP) dynamics and obtained the new bound R_0 > 5.4 ×10^(-11) m at 95% probability for the short-length cutoff parameter. For germanium at the experimental temperature, the parameter-free prescript...

Quantum state revivals, time quasicrystals, and entanglement steering in a Fibonacci-driven central-spin modelTier 3

Motivated by the search for non-equilibrium phases of matter beyond the Floquet paradigm, we propose a route to realize perfect revivals and time quasicrystals (TQCs) in a Fibonacci-driven central-spin model with Ising interactions between the central and satellite spins in the absence of disorder. We analytically demonstrate that when the interaction strength, λ is tuned...

Geometric aspects of fault toleranceTier 3

We highlight three geometric aspects of fault tolerance. First, we construct an operator-algebraic formulation of the fiber bundle framework for fault tolerance, and show that a generalization of the Knill-Laflamme conditions implies a flat connection for this framework. Next, we develop this framework for Gottesman-Kitaev-Preskill (GKP) codes. We show that, for each polariz...

Fast and accurate rare-event simulation by Markov chain Monte Carlo for general quantum codesTier 3

The splitting method estimates logical error rates of quantum error-correcting codes deep in the rare-event regime, where direct Monte Carlo sampling is prohibitively expensive. It relies on a Markov chain Monte Carlo (MCMC) sampler of faulty configurations, usually driven by one-bit-flip proposals. However, one-bit flips have been reported to be trapped on some codes, which...

Benchmarking quantum-annealing-based approaches for factory layout planningTier 3

The earlystage of factory layout planning has a direct effect on the operating costs, efficiency, and productivity of manufacturing systems. Conventional automated planning approaches often face a trade-off between solution quality and computational effort. Recent studies have investigated the potential of quantum annealing (QA) for solving factory layout planning problems....

Multistability and Critical Frustrated Superradiance in Open Anisotropic Quantum Rabi TrimerTier 3

We study the nonequilibrium steady states of an open anisotropic quantum Rabi trimer. Combining semiclassical and quantum mechanical treatments, we map out the system's phase diagram and elucidate the critical phenomena induced by anisotropic light-matter coupling, cavity dissipation, and complex photon hopping, which give rise to abundant multistable phases. Counterintuitiv...

Population Capacity and the Geometry of ThermomajorizationTier 3

We characterize quasiclassical state conversion under thermal operations through population capacities: the maximum population that thermal operations can concentrate on each set of energy levels. These capacities form a normalized, nondecreasing submodular rank function whose base polytope is exactly the thermally reachable population region. Their bounds therefore provide...

Multipartite dynamics beyond bipartite entanglement equilibrationTier 3

Entanglement equilibration need not mark the end of quantum-information dynamics in quantum thermalization. We show that the complete Schmidt spectra of a fixed tripartition can become stationary while its multipartite correlation structure, distinguished by local-unitary invariants, continues to evolve. This separation occurs exactly within a finite window in self-dual kick...

Sublinear thermal state and ground state preparation for free fermions via system-bath interactionTier 3

Dissipative algorithms for preparing thermal and ground states typically require a total Hamiltonian simulation time that grows at least linearly with system size N, even when their mixing time grows only polylogarithmically. We achieve sublinear simulation time for free fermions by engineering local interactions with a bath whose size grows in proportion to the system siz...

Measurement-dependent reduction of open dynamics in the quantum phase estimation algorithm: the visible subspace and the damped Fejér kernelTier 3

For the quantum phase estimation (QPE) algorithm we study the minimal space of observables that is sufficient to predict the entire output distribution under open dynamics of the counting register. Building on the general Krylov theory of reduction, we compute the structure of this space explicitly for the full Fourier measurement. The outcome probabilities are determined by...

Bargmann-invariant witness of the graviton commutatorTier 3

We identify the phase of a Bargmann invariant of two matter-wave interferometers as a quantum gravity signature that cannot be reproduced by any branchwise-definite classical gravitational field. For matter coupled linearly to linearized gravity, the interferometric coherence factorizes exactly into a conservative Newtonian phase, the characteristic functional of the gravito...

Basis-set error bounds for first-quantised quantum simulation of chemistryTier 3

In quantum simulation of electronic structure it is often expected that the estimate of the ground energy converges to the continuum basis limit at a rate of O(N^(-1)) for a basis of size N. This has been found in analytical and numerical studies, but without a rigorous treatment of the error in the quantities considered in quantum algorithms. Here we show the $...

Quantized-resonance description of a quantum emitter dynamics in a lossy multimode cavityTier 3

In the multimode regime of cavity quantum electrodynamics (cQED), light-matter coupling can be strong enough such as to allows a quantum emitter to couple with multiple resonant field modes. This regime leaves distinctive signatures in the behavior of both the field and the emitter, which are already accessible by modern experimental techniques. To model such effects in loss...

Complete characterization of internal-external entanglement trade-offs in two-mode Gaussian statesTier 3

We characterize the exact trade-off between internal and external entanglement in asymmetric two-mode Gaussian states at fixed local symplectic eigenvalues. Internal entanglement is quantified by the negativity N_(A:B) between the two modes, while external entanglement is quantified by the negativity N_(AB:CD) across a Gaussian purification. Numerical...

External-field-modified entropic exchange in confined quantum systems: static versus time-dependent electric fieldsTier 3

We review how external electric fields reshape the information content of spatially confined atoms, and we contrast the response to a uniform static field with that to a monochromatic, time-dependent laser field. The central quantities are the Shannon entropies in position and momentum space, Sr and Sp, and their sum ST = Sr +Sp, which obeys the BBM bound. Using the confined...

Multinomial shot sampling for quantum circuitsTier 3

In classical simulations of quantum circuits, sampling shots (measurement outcomes) from the final state is a routine but costly step. In widely used software, including Qiskit and PennyLane, its cost grows linearly with the number of shots S, even when the simulation has already produced the full state vector, because every shot is generated and processed individually. If...

Charge-Coupled Device-Based Arbitrary Waveform Generation for Qubit ControlTier 3

We propose an arbitrary waveform generation architecture based on charge-coupled devices (CCDs) for qubit control. Waveform samples are stored as charge packets in CCD channels and sequentially clocked out as voltage samples. Multiple channels are operated in parallel and time-interleaved to achieve high effective sampling rates. The generated baseband waveforms are then upc...

Membership in the cone of quantum states over time is NP-hardTier 3

A state over time (stote) pairs a state ρ with a channel E as the Hermitian, generally non-positive operator (ρ⊗1)starJ_E. Characterizing the convex cone Q these operators generate was posed as an open problem in~\cite{HoogstederCalsamigliaWinter2025}. We exhibit a linear copy of the bipartite separable cone as...

Heisenberg-Scaling Quantum Metrology of Electron-Photon Coupling via Multi-Electron PINEMTier 3

Free-electron quantum optics has recently emerged as a promising platform for coherent electron-light interactions, yet its potential for quantum-enhanced metrology remains largely unexplored. Here, we investigate the fundamental precision limit of coupling-strength estimation in multi-electron photon-induced near-field electron microscopy (PINEM), demonstrating that the qua...

Modulation and protection of entanglement in a two-qubit system via two interacting oscillator controlTier 3

We investigate the control and protection of two-qubit entanglement through engineered interactions between two auxiliary harmonic oscillators. Each qubit is coupled to a local oscillator via a dephasing interaction, while the oscillators interact through independently tunable position-position and momentum-momentum couplings. Employing the characteristic-function representa...

Large Language Models for Quantum Code Translation: An Exploratory StudyTier 3

Quantum software development is challenged by quantum-mechanical semantics and fragmented software development kits (SDKs), which complicate cross-SDK code translation and execution. In this paper, we propose an LLM-based approach for translating executable programs between high-level quantum SDKs. We develop a quantum-aware translation workflow whose prompt design and valid...

A General Framework for Leggett--Garg Violation in Neutrino Oscillations and Matter EffectsTier 3

The Leggett--Garg inequality (LGI) constrains temporal correlations under the assumptions of macrorealism and noninvasive measurability. We study the four-time quantity K_4 for two-flavor neutrino oscillations using a pseudo-density matrix (PDM) under static conditions, instead of non-invasive measurement. With this approach, it becomes possible to examine a Horodecki-ty...

Helicity-Selective Electron-Phonon Coupling Between PT-Partner States in 2H-bilayer MoS_2Tier 3

Rotational symmetry (C_n) constrains chiral phonons, but how other symmetries affect their interactions remains largely unexplored. We perform a theoretical and computational study of chiral phonon coupling to parity-time (PT)-degenerate electron doublets in 2H-bilayer MoS_2. Although PT suppresses phonon singlet chirality, chiral phonon doublets can helically inte...

Ramdeobaba University Partners with QClairvoyance Quantum Labs to Establish Dedicated Quantum Software and Hardware FacilitiesTier 2

Central India’s Ramdeobaba University (RBU) in Nagpur, Maharashtra, has signed a Memorandum of Understanding (MoU) with Secunderabad-based deep-tech startup QClairvoyance Quantum Labs Pvt. Ltd. to construct two specialized quantum laboratories on campus. The two-year academic-industrial initiative will establish a dedicated Quantum Software Lab alongside a Quantum Communi...

Intel to Acquire Classiq: Strategic Move Creates Full-Stack Quantum Computing PlatformTier 2

In a significant consolidation within the quantum computing sector, Intel has entered into a definitive agreement to acquire Israeli quantum software provider Classiq for an estimated $2.0 - $2.5 billion in cash and stock. This shows an example of how Israel has established itself as one of the world's most concentrated and effective hubs for quantum technology. Despite i...

Intel to Acquire Classiq to Create a Full-stack Quantum Computing PlatformTier 2

Insider Brief PRESS RELEASE — Intel Corporation today announced that it has entered into a definitive agreement to acquire Classiq, a leading provider of quantum computing software. The combination of Classiq’s synthesis platform with Intel’s spin-qubit manufacturing and existing software would create a user-friendly full-stack quantum computing platform, enabling the...

Israel Ranks Fourth in Private Quantum Investment as Sector Expands, According to ReportTier 2

Insider Brief PRESS RELEASE — A new report by the Israel Innovation Authority and C4IR Israel (which operates within the Israel Innovation Authority and is part of the World Economic Forum’s global C4IR Network), was released today, titled “Israel’s Quantum Ecosystem: Making Quantum Leaps Through Strategic Investment.” The report examines the rapid development of Israe...

Quantum Art Research Outlines More Efficient Quantum Approach to Wave ModelingTier 2

Insider Brief PRESS RELEASE — – Quantum Art, a developer of full-stack, fault tolerant quantum computers based on trapped-ion qubits and a proprietary, dynamically reconfigurable multi-core architecture, recently presented new research, detailed in this paper, that solves wave-propagation problems long thought intractable for classical supercomputers – unlocking new si...

Ramdeobaba University and QClairvoyance Quantum Labs to Set Up Quantum Software and Quantum Communication Labs in NagpurTier 2

Insider Brief PRESS RELEASE — Ramdeobaba University (RBU), Nagpur, and QClairvoyance Quantum Labs Pvt. Ltd., a deep-tech startup based in Secunderabad, have signed a Memorandum of Understanding (MoU) to establish two specialised laboratories on the RBU campus: a quantum software lab and a quantum communication hardware lab. The initiative aims to bring emerging quantum...

Qubit’s Own Electric Current Could Offer a Simpler Readout MethodTier 2

Insider Brief PRESS RELEASE — One of the fundamental challenges of quantum computing is obtaining information from a quantum bit, or qubit. Unlike a conventional bit, which can be read repeatedly without altering its content, direct measurement of a quantum system typically causes the state to collapse before it can be determined. In other words, […]