In briefExact steering boundary and sample-size optimization for averaged hyperon-antihyperon states
SummaryThis paper studies quantum steering, a stricter test of nonclassical spin correlations than entanglement, in hyperon-antihyperon pairs produced by electron-positron annihilation. It determines when steering survives angular averaging and optimizes angular selections to reduce the sample size needed to detect it. The authors derive an exact steering boundary for arbitrary dichotomic projective measurements, which reveals a region missed by the three-setting CJWR criterion, and report a 67.4% reduction in required sample size.
In briefAuditing how LLMs are tested on writing quantum code
SummaryThis paper evaluates 15 large language models on five existing quantum code-generation benchmarks (530 tasks) and on a new benchmark, QuantumBenchEval (96 tasks). The authors report confidence intervals and multiple-comparison-adjusted comparisons. They find that evaluator design can change scores substantially, with models' pass rates rising sharply when certain checks are removed while outputs stay the same. The authors also identify flaws in existing benchmarks that can cause both false failures and false passes, concluding that leaderboard scores alone do not adequately measure progress.
WhyIntroduces a new benchmark and systematically audits evaluator defects, showing scoring design substantially shifts results in quantum code generation.
Ethan Seefried, Romit Ghosh, Sharmin Afrose et al.
In briefGround-state phase maps of Rydberg atom arrays using finite PEPS
SummaryRydberg atom arrays are a promising platform for simulating exotic quantum states, but numerical predictions in two dimensions are difficult, especially when long-range interactions must be treated accurately. This paper applies projected entangled-pair states (PEPS), optimized with a sampling-based method, to debated questions in frustrated geometries. These include spin-glass behavior on the Kagomé lattice and topological order beyond the PXP model on the Ruby lattice. The authors argue that PEPS are well suited for building digital twins of Rydberg atom experiments.
Konrad Schr\"oder, Erik Lennart Weerda, Matteo Rizzi
In briefMajorization for superposition states and the existence of golden states
SummaryThe paper studies superposition resource theory for linearly independent, nonorthogonal reference states and asks when golden states exist and how they look in the Löwdin basis. It proves that Gram majorization is a necessary and sufficient criterion for converting pure states into targets with nonzero coefficients under Kraus-type free operations. For three nonorthogonal reference states, a golden state exists only if the overlaps share a common modulus and the Bargmann phase satisfies a specified inequality.
In briefObserving and controlling light-noise in a heated Rydberg atom electric-field sensor
SummaryThe paper reports optical noise caused by polaritons in a thermal Rydberg atom vapor and shows it can be actively controlled with a radio-frequency field. The noise is amplified in some places and reduced in others across the Rydberg electromagnetically induced transparency resonance, revealing a nonlinear slow-light feedback effect. The authors show that the reference radio-frequency field used in Rydberg heterodyne receivers can set an operating point where high field responsivity and lower optical noise coincide, enabling sensitivity optimization.
Teng Zhang, Lu\'is Felipe Gon\c{c}alves, Alisher Duspayev et al.
In briefKrMM Recurrences: A High-Performance Computing Method for Faster Nonlinear Classical Shadow Estimation
SummaryThis paper addresses the high computational cost of estimating polynomial functions of quantum states with classical shadows. The authors identify a computational kernel in these estimators that can be split row by row and vectorized with custom SIMD code for massive parallelization. Experiments on several tasks show high sequential throughput, near-ideal parallel scaling, and significantly reduced computational cost.
Matthias Gruber, Sabrina Herbst, Ivona Brandic et al.
In briefCo-designing partial fault tolerance for neutral-atom quantum computers
SummaryThis paper co-designs the partially fault-tolerant STAR architecture with neutral-atom hardware, linking atomic physics to logical error modeling and application performance. The authors find a favorable noise bias in 171Yb Rydberg gates and enhance it with error-selective pulse optimization, and they identify a mechanism that suppresses leading-order logical coherent noise. Circuit-level simulations of surface code implementations report logical errors more than an order of magnitude lower than previous estimates. Applied to the periodic Fermi-Hubbard model, the partial approach is shown to offer lower overheads and error rates than fully fault-tolerant methods at moderate error rates of about 10^-3 with a few thousand qubits.
In briefFour-qubit hyperbolic quadric has contextuality degree 315
SummaryThe paper studies the contextuality degree, the least number of Pauli contexts that every noncontextual ±1 assignment must violate. For the four-qubit hyperbolic quadric Q+(7,2), it proves the conjecture from earlier heuristic searches that the degree is 315 and that the violated contexts of every optimal assignment form a dual polar space DW(5,2). The lower bound has a short hand proof, and the characterization of optimal assignments uses a SAT encoding.
WhyProves the four-qubit hyperbolic quadric's contextuality degree is 315, confirming conjectured extremal structure, with a general lower bound and Lean verification.
In briefGiant Rydberg excitons explained as relativistic bound states
SummaryThe study examines the energy-momentum relation of the valence band in Cu2O, an emerging solid host for giant Rydberg states. The dispersion is nonparabolic and can be described using a rest mass of 0.570 times the free electron mass and a rescaled light speed of 1.6×10^5 m/s, resembling relativistic theory. The authors propose a simple expression for bound-state energies of Rydberg excitons with finite quantum defects and attribute these defects to relativistic kinematics.
Mitsuyoshi Takahata, Ikuko Akimoto, and Nobuko Naka
In briefTwo-qubit control of diamond spins using cryogenic CMOS electronics
SummaryThis paper demonstrates two-qubit control of electron and nuclear spins in diamond NV centres using a cryogenic CMOS qubit controller integrated with the diamond device in a cryostat. Gate Set Tomography characterizes single-qubit gate performance and analyzes the main noise processes. Dynamical decoupling is used to build a two-qubit gate, with an estimated electron-nuclear average gate fidelity of 95(2)%.
H. B. van Ommen, N. E. Fakkel, M. van Riggelen et al.
In briefHigher-Order Parity Constraints to Boost Quantum Approximate Optimization
SummaryThis paper studies how specific parity transformations can raise the success probability of the Quantum Approximate Optimization Algorithm (QAOA) on sparse, hardware-native graphs. The authors examine the Signed Max-Cut problem on 3-regular graphs and test it on IBM Heron quantum processors. QAOA parameters are optimized classically on instances with up to 14 vertices, then transferred to instances with up to 40 vertices. According to the paper, with error mitigation, the parity-based QAOA finds optimal solutions for all considered 40-vertex instances, while conventional QAOA fails under the same conditions.
Anita Weidinger, Glen Bigan Mbeng, Roeland ter Hoeven et al.
In briefHigher-order resonances in interacting Stark chains produce long-lived coherent many-body oscillations
SummaryThe paper studies a hierarchy of high-order interaction–tilt resonances in an interacting Stark chain, where the order counts the minimal number of elementary exchange steps. These resonances appear as long-lived coherent oscillations whose timescales depend on the order. By isolating individual resonant channels and building a microscopic effective description, the authors link these timescales to many-body exchange processes and show a strong dependence on the initial-state structure.
In briefLower bounds on generalized metrological sensitivity via squeezing
SummaryThe paper introduces squeezing-type lower bounds for a hierarchy of variance bounds under specific unbiasedness constraints, generalizing the quantum Cramér-Rao bound. It extends standard squeezing coefficients to generalized metrological sensitivities while keeping an experimentally accessible structure. Observables maximizing these bounds can be identified analytically within accessible families. If arbitrary observables are accessible, the optimized bound recovers the exact generalized sensitivity.
In briefQuantum neural networks that correct cloud-cover estimates using physics-based residuals
SummaryThis paper studies compact quantum neural networks for cloud-cover parameterization. Instead of predicting cloud cover directly, it keeps a fitted cloud-cover estimate and learns a correction to its logit in transformed target space. Across ten model variants trained on ICON/DYAMOND-derived data, residual prediction reduced test error relative to direct prediction and beat a selected compact residual multilayer perceptron. A larger, longer-trained Grundner-Q1 model achieved lower error, so the authors frame the results as a boundary, not evidence of quantum advantage or online climate-model skill.
In briefUniversal quantum criticality from a Gaussian variational manifold: a noninteracting fermion method for quantum phase transitions
SummaryThe paper presents a systematic way to find the best noninteracting fermionic description of a quantum phase transition using fermionic Gaussian states. Tested on the interacting long-range transverse-field Ising chain, the method reduces to a self-consistent Euler equation whose critical line closely matches independent numerical benchmarks. Accurate critical predictions emerge even though Gaussian-state fidelity to the exact ground state is lowest near the transition.
Reyhaneh Khasseh, Fabian Ballar Trigueros, Markus Heyl et al.
In briefExperimental probing of strong-to-weak symmetry breaking transitions in mixed quantum states on a superconducting processor
SummaryThis paper experimentally examines finite-size critical signatures of strong-to-weak spontaneous symmetry breaking transitions on a superconducting quantum processor. The authors combine quantum measurements with classical processing based on a known dephasing channel to reconstruct nonlinear mixed-state correlators. They observe finite-size crossings and scaling collapses under power-law-correlated dephasing, along with signals of mixed-state symmetry-protected topological phases.
WhyExperimentally resolves finite-size critical signatures of strong-to-weak symmetry breaking on a superconducting processor, with classical reconstruction of nonlinear correlators and clear scaling evi
Zhi-Yuan Wei, Christopher Fechisin, Yu-Xin Wang et al.
In briefFundamental memory limit of noisy quantum reservoirs
SummaryThis paper studies how long a noisy quantum reservoir can retain memory. When k input qubits are reinitialized at each time step under depolarizing noise, the longest achievable memory is exp[Θ(k)] time steps, regardless of the reservoir's size, dynamics, or input encoding. The authors provide a universal upper bound and an explicit reservoir that reaches this exponential scaling, establishing the optimal resource law.
WhyProves a universal exponential memory bound for noisy quantum reservoirs and an attaining construction, a strong theoretical advance with focused impact.
Markus Baumann, Jonas Stein, Claudia Linnhoff-Popien
In briefSidewall Metrology Protocol for Superconducting Qubit Devices: A Scanning Probe Method for Measuring Qubit Sidewall Shape
SummaryThis paper presents a scanning probe microscopy-based framework for quantitatively characterizing the sidewall morphology of superconducting qubits. It introduces a refined root mean square lateral roughness descriptor and a curvature-equivalent radius for describing vertical sidewall shape. These descriptors and measurement procedures are applied to different qubit device components, forming a proposed characterization protocol. The authors suggest it provides a basis for comparing fabrication processes across laboratories and studying links between sidewall geometry and qubit performance.
J{\o}rgen Garn{\ae}s, Henrik S. Guttesen, Astrid T. R{\o}mer et al.
In briefA theory of approximate Heisenberg propagation that accounts for measurement readout error
SummaryThis paper studies classical methods that estimate quantum expectation values by propagating observables in the Heisenberg picture, such as Pauli propagation, Lie-algebraic simulation, and Krylov subspace methods. The authors introduce a unified framework called generalized Pauli propagation and use weighted commutator graphs to derive exact identities linking approximation errors to discarded operator components. They introduce the concept of delayed observability and prove that, under suitable symmetry conditions, keeping the symmetry-preserving part of a weak perturbation removes first-order expectation-value errors.
Yubraj Bhandari, Jakob S. Kottmann, Adelina B\"arligea
In briefWave-particle duality in quantum walks, viewed through quantum mechanics
SummaryThis paper revisits the quantum walk, a quantum version of a random walk, from a quantum mechanical perspective, following Feynman's path integral toy model. It shows particle-like behavior through reflection and partial reflection, and wave-like behavior through interference. For an initial state on two sites ±ℓ, the authors derive the weak limit distribution of the Hadamard walk and show the Konno distribution is modulated by the factor 2cos²(ℓk(x)).
Norio Konno, Shigeki Matsutani, Etsuo Segawa et al.
In briefQuantum control reframed as a renormalization group flow
SummaryThe paper applies the renormalization group idea from Hamiltonian physics to quantum control, building a flow through the space of time-dependent Hamiltonians. A control subspace of experimentally accessible terms forms the fixed-point manifold, and the flow preserves the target unitary while monotonically reducing Hamiltonian weight outside that subspace. The authors also introduce flow-equation engineering and demonstrate the framework on nonperturbative Floquet engineering of the Haldane model and accessible fast-forward driving of transverse-field Ising chains.
Zuo Wang, Paul M. Schindler, Modesto Orozco-Ruiz et al.
In briefEnhanced charging in open Rabi and Dicke quantum batteries: a study of whether direct incoherent pumping can stabilize charging in quantum batteries.
SummaryThe paper studies charging of Rabi and Dicke quantum batteries under direct incoherent pumping, modeled by a Lindblad master equation. For a single Rabi battery, pumping suppresses coherent energy backflow, broadens the high-energy charging window, and improves robustness to timing errors and detuning. For finite Dicke batteries, the strongest pump considered increases peak stored energy and ergotropy per cell and improves near-peak timing robustness, while average charging power also rises, though that metric includes pump-assisted jump contributions.
In briefMulti-path Security in Quantum Networks with Trusted Nodes: Keeping quantum communication safe when some relay nodes may be compromised
SummaryQuantum networks lose their information-theoretic security if relay nodes are compromised, and such nodes are hard to identify. The paper shows that multi-path routing offers quantifiable protection against unidentified compromised nodes. It also analyzes network and node security under full and partial compromise, optimal edge placement, and hacking probability across topologies. Applied to quantum key distribution, the framework identifies strategies for secure, reliable communication without quantum memory.
In briefDistributed quantum circuit execution using pre-shared entanglement across quantum networks
SummaryThis paper studies how to split a quantum circuit across a network of quantum devices to improve scalability. Inter-node gates need entangled qubit pairs, but creating them during execution is slow and can cause decoherence of logical qubits. The authors propose pre-distributing some entanglement pairs under a budget, then allocating qubits to memory to minimize expected execution time. Additional pairs are generated concurrently during execution as needed. The methods are evaluated on a broad range of benchmark circuits.
In briefLIDAR using optically amplified thermal light
SummaryThermal light shows intensity fluctuations (photon bunching) but its low spectral density limits practical uses such as LIDAR. The authors use optical amplification to boost its brightness and show that the normalized second-order coherence function g(2)(τ) of the thermal source is preserved after amplification. Using the amplified thermal light, they demonstrate a LIDAR raster scan of a building at 1.3 km with a 2 cm depth resolution.
Darren Ming Zhi Koh, Peng Kian Tan, Christian Kurtsiefer
In briefHyQ-LC: Hybrid quantum-classical learning for classifying star brightness patterns
SummaryThis paper presents HyQ-LC, a model that classifies stellar light curves into ten classes using 359 handcrafted features and 633,034 training objects. It combines a window multilayer perceptron with a nine-qubit quantum readout and compares it against a pure MLP with the same 44,238 parameters. The hybrid shows small point-estimate gains in Macro-F1 on a shared test set, but the specific contribution of the quantum branch is unresolved, and all circuits are simulated classically.
In briefTime-resolved absorption spectroscopy using quantum light
SummaryThis paper presents a complete quantum theory of time-resolved transient absorption spectroscopy, describing how a nonequilibrium target linearly responds to quantum probe fields beyond the semiclassical approximation. It shows how quantum correlations between probe-field frequency modes couple to coherences in the target and gives a simple expression for computing the resulting spectroscopic signals. The authors also identify conditions under which quantum light can alter transient absorption spectra beyond what classical fields can achieve.
In briefA dual-satellite design for longer-distance quantum entanglement sharing
SummaryThis paper proposes a network design where two ground stations send entangled photons up to two satellites, linked by an inter-satellite link, to distribute entanglement over long distances. It compares this design with a single-satellite setup under the same physical assumptions, including geometric loss, atmospheric turbulence, background noise, and Bell-state measurement efficiency. The authors report that the single-satellite option suits regional networks but becomes infeasible at large separations, while the dual-satellite design significantly extends the achievable distance.
In briefConjugate measurement-induced evolution toward maximally mixed states in quadratic quantum systems
SummaryThis paper extends earlier work on the interaction-dominant case to the full quadratic dynamics of a single-mode subsystem coupled to a two-mode environment. Each conjugate variable of the subsystem couples to a distinct environment mode. Using exact reduced Weyl characteristic and Wigner functions, the authors identify the phase-space mechanism behind the asymptotic behavior. Under finite-volume and momentum regularization, the reduced subsystem approaches a maximally mixed state.
In briefBlock encodings that handle many molecular geometries at once for quantum computing
SummaryThis paper introduces SVD-THC, which extends tensor hypercontraction to Hamiltonians defined at different nuclear geometries by using a singular value decomposition of the ensemble. The authors build a single multiplexed block encoding circuit covering all geometries and test it on 1-bromo-2-chloroethane, glycine and alanine dipeptides, with up to 5,184 geometries. They report that Toffoli complexity grows only weakly with ensemble size, giving 35 to 200 times fewer Toffoli gates than slicing together single-geometry block encodings in an energy-thresholding circuit.
Cristian L. Cortes, Andrew J. Jenkins, William Pol et al.
In briefQuantum entanglement for measuring fast-changing signals across a wide frequency range
SummaryThis paper studies using entangled quantum probes to measure signals that change over time. Entanglement's sensing advantage for static signals is usually erased by dephasing. Using classical white noise as the example, the authors show that entanglement can widen the measurable bandwidth by a factor of N without losing sensitivity. Alternatively, over a fixed bandwidth, it reduces average estimation uncertainty by a factor of √N compared with separable states.
In briefHow Quantum Is Light? A Review of Measures and Uses of Optical Quantumness
SummaryThis review paper examines how to quantify the quantumness of a state and which traits distinguish quantum states from classical ones. It frames state characterization through both theoretical and operational perspectives. The authors argue that certifying quantumness is a practical necessity for identifying and realizing quantum advantage in real-world applications.
Soumyakanti Bose, Hyukjoon Kwon, Yong Siah Teo et al.
In briefReview of quantum computing methods for plasma physics in magnetic-confinement fusion
SummaryThis paper reviews existing quantum computing studies on simulating plasma in magnetic-confinement fusion, covering kinetic dynamics, wave interactions, equilibrium, and macroscopic stability. It evaluates hardware implementations and operational bottlenecks. The authors note that current work is mostly limited to linearized equations, reduced models, or isolated subroutines, leaving a large gap from realistic fusion simulations. The paper also identifies problem characteristics likely to yield quantum advantage and outlines a roadmap toward practical advantage.
In briefNon-planar contact structures, Calabi-Yau fillings and topological quantum computation
SummaryThis paper extends the author's earlier work on planar contact structures and topological quantum computation to non-planar surfaces of genus g with connected binding. Every maximal system of disjoint liftable arcs contains exactly g arcs, leaving two branch points unused. The half-twist between those two points is not liftable, though its cube is and lifts to the identity. The paper also gives an integral residue criterion for Calabi-Yau fillings.
In briefOnline scheduling of quantum circuits across quantum networks
SummaryQuantum networks can link small, noisy quantum processors to perform distributed quantum computing. This paper studies the realistic case where quantum circuits arrive as a stream, and formalizes an online problem: deciding which waiting circuits to launch and how to place their qubits without knowing future arrivals. The system must account for finite memory, probabilistic entanglement generation, and decoherence. The objective is to minimize mean completion time and makespan.
In briefPerturbation theory for quantum information measures of Gaussian states
SummaryThis paper develops a unified perturbation theory, within the Gaussian-state formalism, for the von Neumann entropy, quantum relative entropy, quantum Chernoff quantity, and quantum fidelity, deriving second-order expressions. It shows the perturbative quantum Chernoff quantity is maximized at its symmetric point, giving the quantum Chernoff exponent. The framework is applied to quantum illumination and incoherent-light sub-Rayleigh object discrimination, recovering known asymptotic exponents.
In briefMeasuring the Quantum Phase of Multiphoton Systems
SummaryThe paper reports the first measurement of the quantum phase of multiparticle systems containing up to fifteen particles. The authors combine homodyne interferometry with photon-number-resolving detection in a new quantum state tomography scheme. This allows them to reconstruct photon-number and phase representations and establish the corresponding number-phase uncertainty relation. The work also gives access to a multiparticle mutually unbiased basis and reports spatially resolved phase characterization.
Ian Baum, Riley B. Dawkins, Jannatul Ferdous et al.
In briefDistributed Phase Tags: a real-valued compiler for multi-party quantum programs
SummaryThe paper addresses how to simulate complex quantum amplitudes over real Hilbert spaces in multi-party programs without a globally shared auxiliary system. It gives each party a local phase tag and a real operator J=XZ that acts logically as multiplication by i. The authors prove the translation preserves computational-basis measurement probabilities and the run-time interaction graph, and illustrate correctness on the three-party GHZ program.
In briefSubsystem quantum Rényi-Bhattacharyya distance in 2D CFTs and its holographic applications
SummaryThe paper presents a systematic method to compute subsystem fidelity and Rényi fidelity in two-dimensional conformal field theories using the operator product expansion of twist operators. The method is applied to the quantum Bhattacharyya distance and Rényi-Bhattacharyya distance, validated against exact free fermion and boson results. In holographic CFTs, states differing in classical order-c data are distinguishable at the level of classical gravity, while states with matching leading data yield order-1/c distances, a perturbative quantum gravity effect.
In briefFinding Hidden Quantum States with Classical Interactive Advice: A Lower Bound
SummaryThis paper studies whether a quantum verifier can find a hidden quantum state by exchanging classical messages with an unbounded prover who knows the state. For a Haar-random n-qubit target, the authors prove that constant average fidelity requires (q+1)^2(B+1)=Ω(2^n), where q is the number of verifier queries and B the total prover-to-verifier communication. The bound allows arbitrary classical interaction. This yields a unitary oracle separating QMA from QCIP, and the separation holds even for UniqueQMA.
WhyExtends Aaronson-Kuperberg's lower bound to arbitrary classical interaction and yields a QMA versus QCIP quantum-oracle separation; rigorous proof, though limited to Haar-random targets.
In briefNoise in nanolaser amplification: from discrete emission events to the additive limit
SummaryThis paper studies random fluctuations in laser amplification when the cavity holds only a few photons, using a single-mode photon-carrier model. It describes the dynamics with a state-dependent multiplicative Gaussian-noise framework based on discrete transitions. The model is compared with an event-based Laser Markov Chain, which agrees well when a continuous diffusion description holds, while the discrete model is needed at low photon numbers. At large photon counts, the standard Langevin description is recovered.
In briefCertifying randomness using statistically hiding commitments
SummaryThe paper studies how a classical verifier can certify that an untrusted quantum device produces randomness that stays unpredictable even to an adversary holding quantum side information. Building on a commitment-based proof of quantumness from one-way functions, it shows that statistical hiding with ordinary computational binding suffices. This yields a protocol from post-quantum statistically hiding bit commitments, which can be instantiated with claw-free functions or in the quantum random oracle model.
WhyIntroduces quantum virtual-input hiding and proves statistically hiding commitments suffice for randomness certification against quantum side information, with several instantiations.
In briefCryogenic recharacterization of a commercial 22 nm FD-SOI standard-cell library for 4 K digital control
SummaryThe paper addresses wiring and bandwidth bottlenecks between quantum processors and room-temperature electronics by placing digital control at 4 K, using a commercial 22 nm FD-SOI standard-cell library recharacterized with commercial cryogenic device models. Original cells and flows are retained. Zero body bias raises median delays by 38.6x (rising) and 33.0x (falling) versus full bias, with about 90% of transitions exceeding the foundry maximum-transition limit. In post-route analysis of a fabricated 32-bit ALU, the register-to-register frequency rises from 1.3 MHz at zero bias to 132.9 MHz at ±1.8 V.
Mohamed Gharib, Rami Rasheedi, Salma Abdelzaher et al.
In briefTopological quantum gates on fractional Chern insulators with bounded quantum metric
SummaryThis paper studies the topological order of two-band 2D fractional Chern insulators. The authors show that bounding the integrated quantum metric along one Brillouin-zone cycle refines the order into |C| braiding observables that lattice translations cyclically permute. They classify quantum gates that could in principle be implemented on this order, including the non-Clifford T-gate and CCZ-gate.
In briefCertifying particle indistinguishability in interferometers without tailored hardware
SummaryThe paper proposes a scalable, efficient in situ method to test whether identical bosons or fermions are indistinguishable in linear interferometer experiments. It applies to any generic linear interferometer. For particles in distinct input ports of a Haar-random unitary interferometer, the required number of runs scales polynomially with particle number, interferometer size, and inverse precision, with high probability. The method remains polynomial under uniform particle loss if the inverse single-particle survival probability is polynomially bounded.
WhyProposes a scalable in situ certification using bunching effects with polynomial scaling proofs; novel and impactful for Boson Sampling, though evidence is mainly theoretical.
In briefSqueezing and decoherence in axion dark matter, a quantum feature of light dark matter
SummaryThis paper studies quantum squeezing of light axion-like dark matter fields. Gravitational self-interactions can squeeze the field, creating quantum features beyond the classical description. The authors show squeezing is continuously generated fast enough to survive dissipation and may persist under thermal fluctuations and dephasing. They suggest dark matter may have persistent quantum features worth exploring for detection.
In briefA survey of Rydberg atomic receivers for wireless physical-layer communication and sensing
SummaryThis survey reviews Rydberg atomic receivers, which use highly excited alkali atoms to measure electromagnetic fields as an alternative to classical electronic receivers. It covers the technology's evolution, underlying mechanisms, advantages and challenges, and experimental configurations. The paper also examines electric-field detection methods and recent progress in communication, sensing, and radar-like applications, and concludes by summarizing promising research directions.
In briefReal-time quantum simulation of how hadrons are produced in deep inelastic scattering
SummaryThe paper presents a quantum simulation framework for meson production in deep inelastic scattering, based on the light-front QCD Hamiltonian formalism. A quark-antiquark dipole is evolved in real time through the color field of proton and gold nuclear targets using Trotterized unitary evolution. From the evolved state, the authors extract transverse momentum broadening, cross sections, the J/ψ production rate, and the nuclear modification factor R_A.
In briefCan quantum entanglement raise the capacity of classical relay channels?
SummaryThe paper studies classical relay channels assisted by entanglement. For a unit-delay relay with strictly causal encoding, the authors show that the standard cutset upper bound still holds with entanglement assistance, so entanglement does not increase capacity for several classes of such channels. For a zero-delay relay with causal encoding, they present an example where entanglement shared between source and relay enables rates at least 12.5% above the cutset bound, significantly increasing capacity.
WhyShows entanglement lets zero-delay relay rates exceed the cutset bound by 12.5%, a notable theoretical advance with proofs.
In briefBreakdown of disjoint additivity under magnetic Gauss constraints
SummaryThis paper examines whether, under local magnetic Gauss constraints, observable algebras of vertex-disjoint regions that commute still generate all observables on their union. The authors construct counterexamples for every finite non-Abelian group on regular square tori. For a fixed eight-edge square loop, additivity fails exactly when the group is non-Abelian and each inner face is covered by one of two prescribed peripheral edges. These results refute a recent proposition on group-double additivity.
