June 23, 2026

Emergent Andreev Reflection from a Lattice Duality Defect

Andreev reflection converts an incoming fermion into an outgoing hole and is usually tied to a superconducting interface. We show that an analogous charge-conjugating boundary condition emerges from a purely lattice duality defect. Starting from a Majorana representation of the transverse-field Ising chain, we construct a folded lattice model in which a boundary Majorana imp...

Multi-scale reconstruction of single-ion damage tracks in diamond via nitrogen-vacancy centers

Understanding particle-induced damage tracks in solid-state materials underpins emerging applications in rare-event detection and quantum defect engineering. Resolving these tracks requires multi-scale readout, from event localization at the millimeter scale to track-morphology reconstruction at the nanoscale. Nitrogen-vacancy (NV) centers in diamond provide such a platform,...

A quantum algorithm for one-shot signatures

We provide a pre-obfuscation circuit-level implementation of an efficient one shot signature scheme, which has known applications to delegated signatures, secured token transfer, and publicly verifiable randomness. The algorithm consists of two stages: a key generation stage where a classical public key/quantum secret key pair is produced, and a signing stage where the quant...

Efficient Energy-Constrained Semi-Device-Independent QRNG with an Integrated Heterodyne Receiver

Semi-device-independent QRNG frameworks represent a particularly attractive approach, combining strong security guarantees with high randomness generation rates while relying only on reduced and practical physical assumptions. A recently proposed approach based on photon-number constraints is particularly suited to photonic implementations, where these assumptions can be eas...

Chaos Generation and Control with Molecular Optomechanical System

Chaos is central to secure communication and physical random-number generation. Conventional cavity-optomechanical implementations, however, usually rely on weak single-photon optomechanical coupling and low-frequency mechanical modes, so access to deterministic chaotic dynamics often requires large driving power and careful suppression of thermal noise. Here we theoreticall...

Bunny Codes: Broadening Superconducting Quantum Error Correction Capability through Advanced Control Engineering

Drawing on advances in superconducting qubit control schemes that unlock enriched native gate sets at the hardware level, we systematically examine how harnessing this enlarged physical two-qubit gate pool -- specifically CNOT and CXSWAP -- streamlines syndrome extraction for certain qLDPC codes with nonlocal stabilizers. Through an exhaustive search, we discover a set of qL...

Linear optical Bell state measurement for rotation-symmetric cat codes

Rotation-symmetric cat (RS-cat) codes are a bosonic-code platform for quantum information processing, combining finite-energy realizability with robustness against photon loss through their discrete rotational symmetry. For applications in long-distance quantum communication and fusion-based quantum computation (FBQC), efficient Bell state measurement (BSM) is a key primitiv...

All-optical Implementation of Generalized Quantum Teleportation

Measurement-based continuous-variable optical quantum computing inherently offers high-speed, large-scale operations, yet its practical performance remains constrained by the processing latencies and throughput bottlenecks imposed by classical electronic feedforward circuits. To overcome these limitations, we propose a loss-tolerant, all-optical feedforward (AOFF) architectu...

Structure and information measures of few-electron systems under a spherically symmetric Gaussian potential within a density functional approach

Energies of H, He-like (Z=2-18) ions, Li, and Be are investigated under a spherically symmetric Gaussian potential through a density functional formalism. The radial Kohn-Sham equation has been solved by invoking a work function-based exchange potential. The effect of electron correlation is analyzed by incorporating two functionals: a local parameterized Wigner functional...

Improved State Readout in NV Centers using Regression Models and Rabi Driving

Readout of state populations in nitrogen-vacancy centers from fluorescence measurements at room-temperature is routinely achieved via contrast-based calibration. The fidelities achieved by this conventional approach are limited by reducing the dynamical fluorescence behaviour of the NV center to a scalar value, and calculating the population of each possible state independen...

Quantum Convolutional Neural Networks for Groundwater Heat Plume Prediction: A Surrogate Modeling Approach

Quantum machine learning methods are increasingly explored for modeling complex environmental systems, including groundwater heat plume dynamics. In this work, we explore a Quantum Convolutional Neural Network (QCNN) as a surrogate model for predicting temperature variations in groundwater induced by geothermal heat pumps in the city of Munich. To comply with the scalability...

Adversarial Reinforcement Learning for Adaptive Eavesdropping in BB84 Quantum Key Distribution

BB84 quantum key distribution derives its security from a physical guarantee that any eavesdropper disturbs the channel in a statistically detectable way. Prior work evaluates this by assuming Eve attacks at a fixed, analytically optimized rate. We examine what happens when Eve is modeled instead as a learning agent. Classical reinforcement learning is used, specifically tab...

When the Learning With Errors Problem Meets the Coherent Ising Machine: A Penalty-Free Algorithm-Hardware Co-Design

The Learning With Errors (LWE) problem constitutes the mathematical foundation of modern Post-Quantum Cryptography (PQC). Cryptanalysis of LWE ranges from classical lattice reduction to machine learning and quantum-classical hybrids. We propose CIM-BDD, a hybrid Bounded-Distance-Decoding solver that reduces LWE to a Quadratic Unconstrained Binary Optimization (QUBO) problem...

Isometrization of Tensor Network States via Gauge Propagation

We introduce a gauge-propagation approach for approximately converting generic tensor-network states into an isometric tensor-network state form with a prescribed orthogonality center. In one dimension, this propagation is exact because the non-isometric factor produced by a QR or singular-value decomposition is supported on a single virtual bond. In higher-dimensional netwo...

An interpretable closed form for entanglement entropy from bitstrings, guided by a graph neural network

The empirical bitstring distribution is the most accessible observable on Rydberg-atom arrays, but the bipartite von~Neumann entropy it constrains is far costlier to obtain. We present a six-term linear closed form for the entropy, built on bitstring-derivable physics scalars, and characterize its accuracy, portability, scaling behaviour, and calibration cost. The feature se...

Prethermal rotating-frame solid echo in a dipolar nuclear-spin network

Floquet prethermalization can endow interacting quantum solids with long-lived, approximately conserved quantities, enabling Hamiltonian engineering and new dynamical probes. Using a hyperpolarized network of dipolar-coupled ^(13)C nuclear spins in diamond driven by pulsed spin-locking, we access a rotating-frame prethermal plateau with quasi-conserved transverse magnetiza...

Wess-Zumino terms in 0+1 SU(N) superspin systems

These notes present a self-contained introduction to Wess-Zumino (WZ) terms in quantum systems with SU(N) symmetry, emphasizing the interplay between geometry, topology, and condensed-matter applications. We begin with the SU(2) spin coherent-state path integral, where the Berry phase appears as a WZ term encoding the symplectic structure of the Bloch sphere. This exampl...

Protecting Qubits from Purcell Decay via Permanent Dipoles

Reading out a qubit often requires coupling it to a resonator, but that same resonator can also give the qubit an extra path to decay. Here, we study a way to reduce this loss using a built-in permanent electric dipole. The dipole shifts the cavity field in different directions for the qubit ground and excited states. This shift makes the relevant wave functions overlap less...

President Trump Signs Two Executive Orders on Quantum Technology

President Donald J. Trump has signed two Executive Orders aimed at cementing American leadership in the quantum era. Together with their accompanying Fact Sheets, the directives lay out a strategy designed to protect the nation from advanced cryptographic attacks while simultaneously encouraging commercial and scientific quantum innovation. Here is a breakdown of key prov...

Podcast with Helmut Katzgraber, General partner at 55North

Yuval Boger interviews Helmut Katzgraber, general partner at 55North and former quantum leader at AWS. They discuss Helmut’s view that the most promising near- to mid-term quantum applications are in quantum simulation for materials, chemicals, and pharma, rather than optimization. They also explore European competitiveness, venture opportunities across the quantum stack,...

Infleqtion Launches America’s Quantum Space Initiative to Develop Orbital Technology Infrastructure

Neutral-atom developer Infleqtion (NYSE: INFQ) has launched America’s Quantum Space Initiative to accelerate the deployment of quantum technologies within the aerospace sector. The public-private coalition brings together a group of founding innovators, including Voyager Technologies, Monarch Quantum, Armada, and the University of Colorado Boulder. Operating through a col...

IBM Nighthawk Processor Validated in Quantum Chromodynamics and Cybersecurity Benchmarks

Independent researchers from the IBM Quantum Network have published two separate technical studies validating real-world applications on the IBM Nighthawk quantum processor framework. Orchestrated through the RPI-IBM Future of Computing Research Collaboration, the peer-reviewed papers demonstrate scalable, hardware-native executions across particle physics simulations and...

Duke University and IonQ Demonstrate Tripartite Entanglement of Remote Atomic Qubits

Researchers from the Duke Quantum Center and IonQ have demonstrated the distributed generation of a Greenberger–Horne–Zeilinger (GHZ) state across a three-node quantum network using individual trapped atomic ions. The experimental configuration consisted of three spatially separated hardware modules positioned approximately 2 meters apart, linked by 3-meter single-mode op...

Robust Structure Learning of k-local Lindbladians

We present an efficient protocol for learning an unknown k-local Lindblad generator on n qubits using only product-state preparations, short-time evolution, and single-qubit Pauli measurements, without prior knowledge of the interaction structure. For fixed k and bounded weighted interaction strength, the protocol estimates all Hamiltonian and dissipative Pauli--GKSL c...

Genuine certification of incompatible quantum instruments through sequential communication tasks

Quantum instruments constitute the general description of quantum dynamics, encompassing both quantum measurements and quantum channels as special cases. Consequently, the incompatibility of quantum instruments represents a fundamental manifestation of nonclassicality in quantum theory. Here, we establish the operational significance of this notion by demonstrating communica...

Log-concavity and tunneling: adiabatic quantum optimization for convex functions (with a spike)

Quantum tunneling is expected to provide a computational speedup in quantum computing, a phenomenon that Adiabatic Quantum Optimization (AQO) aims to leverage. While some academic proofs of concept have been studied, such as the "Hamming weight with a spike" (HWS) problem, the algorithmic gains of this effect remain underexplored. In this work we extend the analysis underlyi...

Random dimension reduction and learning symmetric properties of quantum states

We introduce a procedure called random dimension reduction that simultaneously reduces the dimensions of many, potentially distinct quantum states while preserving properties invariant under the tensor power action of an isometry. This provides a black-box method to replace the dimension with the maximum rank in the sample complexity of learning symmetric properties, even th...

Genuine Global Kochen-Specker Contextuality as Classical Coordination Cost

Classical simulations of quantum correlations can fail because no low-communication local hidden-variable model exists, or because no single noncontextual hidden state can explain all compatible measurement contexts. This manuscript studies a third regime: genuine global Kochen-Specker contextuality, where local subsystems are noncontextual and the tested multipartite blocks...

Structure-Aware Variance Reduction for Unbiased Randomized Hamiltonian Simulation

Randomized Hamiltonian simulation methods are often governed by a trade-off between systematic bias and sampling overhead. We study how classical variance-reduction techniques can be applied to such methods without changing their mean channel, and therefore without introducing additional bias. As a motivating unbiased estimator, we formulate continuous time-evolution probabi...

How Stark units enter SIC overlaps

It has been observed that the mutual scalar products of the vectors in a SIC-POVM are given by algebraic units, and at least in some cases by square roots of Stark units. The full picture is somewhat more complicated, especially if non-minimal SIC-POVMs are considered. We present a mixture of exact and numerical evidence suggesting that the overlap units are always products...

Dissipative preparation of Laughlin-like states

Fractional quantum Hall (FQH) states are a central paradigm of strongly correlated quantum matter and a key platform for topological quantum computation. Here, we propose a purely dissipative protocol based on local loss and pump channels for preparing Laughlin-like states at filling 1/3, with a possible extension to other 1/M filling states. We show that Laughlin-like s...

Full-Field Mode Sorter for Optical Knots

Optical knots are topologically structured light fields whose phase or polarization singularities trace linked or knotted trajectories during propagation, making them promising candidates for high-dimensional optical information carriers. Their use in communication or quantum-information protocols, however, requires a practical readout method that can distinguish a chosen kn...

On the cryptographic potential of single-qubit rotations

In the domain of quantum communication, cryptographic protocols often require users to have access to trusted qubit sources or detectors. Recently, it was shown that on an architecture called the Qline, several protocols can equivalently be performed by parties capable only of single-qubit rotations. In this work, we introduce two composably secure constructions that togethe...

Bounding Classical and Quantum Correlations in Bayesian Networks with Quasiprobabilities

Bell's theorem reveals that quantum theory is in tension with classical causal reasoning and, in particular, the notion of local causality. This is now understood as a particular example of non-classicality in the study of correlations in (Bayesian) networks with both unobserved and observed nodes: the correlations are probability distributions over the observed nodes. There...

Ultra-Peripheral Collisions as a Nuclear-Structure Interferometer with Interpretable Multitask Deep Learning

Precise knowledge of nuclear structure is essential across fundamental physics, yet probing these structures is notoriously difficult. To address this challenge, ultra-peripheral collisions (UPCs) provide a femtoscopic tomography for imaging the atomic nucleus. UPCs offer a pristine electromagnetic pathway: coherent vector-meson photoproduction generates patterns of diffract...

Irreversibility Enhances Quantum-Enhanced Markov-Chain Monte Carlo

Detailed balance underlies conventional Markov-chain Monte Carlo (MCMC) algorithms. Yet in classical systems, breaking detailed balance generates irreversible probability currents and can accelerate sampling. Whether irreversibility can similarly enhance quantum MCMC remains an intriguing question. Here we show that irreversibility provides a new route to improving the recen...

The adaptive nature of confirmation bias

In this paper, the phenomenon generally classified as confirmation bias is formulated on the space of square-root probabilities (or equivalently, using the structures of quantum probability). In this framework, observations are modelled by matrices, rather than random variables on a probability space. In the problem of binary hypothesis testing, an optimal evidence choice mi...

Fast quantum-state transfer in Su-Schrieffer-Heeger chains beyond the noninteracting regime

Shortcuts to adiabaticity have made topological edge-state transfer fast in the single-particle regime, but their extension to interacting systems is obstructed by nonlinear phase accumulation. We show that this obstruction can be removed in Su-Schrieffer-Heeger chains by making the next-nearest-neighbor shortcut hopping phase tunable. In the mean-field regime, this yields a...

Jacobi exceptional orthogonal polynomials for extended Scarf I potentials with position-dependent mass

We show that the Scarf I potential problem in a position-dependent mass background of the type m(α;x) = (1 + αsin x)^(-2), 0<α<1, can be solved by using a point canonical transformation mapping the corresponding Schr\" odinger equation onto that of the Scarf I potential with constant mass. The inverse point canonical transformation then provides some exactly-solvable ra...

Tuning Quantum MPS

Matrix Product State (MPS) methods are among the most effective approaches for the classical simulation of quantum circuits, but their practical performance depends strongly on simulator hyperparameters, and default settings are often suboptimal. In this work, we propose a two-stage framework for automatic hyperparameter selection for quantum MPS simulation. In the first sta...

Quantum Key Distribution Without Shared Reference Frame Under Unital Noise

We consider a general and practical scenario of quantum key distribution (QKD) over an unknown, stationary, unital qubit channel. Furthermore, due to practical limitations, e.g., relative movement and rotation of communicating parties, a global shared reference frame cannot be established. This scenario can routinely appear in satellite QKD. We propose two methods to overcom...

Quantum Advantage in Tolerant Junta Testing

We establish the first super-polynomial quantum advantage for the tolerant junta testing problem in the adaptive setting. Specifically, we show that within a certain parameter regime, tolerant k-junta testing with high precision can be solved using poly(k) quantum queries, whereas any classical algorithm requires at least k^(Ω(log k)) queries. The problem of...

Entropic Uncertainty Relations for Mutually Unbiased Operator Frames

We develop an operator-frame formulation of entropic uncertainty relations in the Hilbert-Schmidt space of operators. For general continuous indexed operator frames, we derive an entropic uncertainty relation for the associated coefficient distributions by combining endpoint norm estimates with Riesz-Thorin interpolation. We then identify a distinguished class of mutually un...

Angular-time evolution and edge-spin dynamics in the Haldane phase of the S=1 bilinear-biquadratic chain

We investigate the angular-time evolution -- a parameter-time evolution generated by the entanglement Hamiltonian -- for the bipartitioned ground state of the S=1 bilinear-biquadratic chain under the open boundary condition with the up edge spin. Using a matrix-product-state representation of the ground-state wavefunction, we calculate the angular-time spin correlation funct...

Understanding Squeezed States of Light Through Wigner's Phase-Space

This paper starts with the transition from classical physics to quantum mechanics which was greatly aided by the concept of phase space. The role of canonical transformations in quantum mechanics is addressed. The Wigner phase-space distribution function is then defined which arises from the formulation of the density matrix, followed by the harmonic oscillator in phase spac...

An Efficient and Perfect Secret Sharing Scheme on a Class of Non-Maximal Quantum Access Structure

Quantum secret sharing is one of the core security technologies in the field of quantum communication. Aiming at the problems of high quantum resource consumption and the difficulty in balancing security and efficiency existing in current quantum secret sharing schemes under non-maximal quantum access structure(QAS), this paper focuses on the judgment criteria of non-maximal...

Satellite Mission Planning with Rydberg Atoms

Quantum computers relying on cold atoms are being built and promise a high flexibility in the way information in encoded into the physical system. In particular, the analog mode is spiking interest in the field of optimization as a classically intractable number of configurations can be tackled. In this work, we investigate a problem that requires every-day scheduling of cri...

Wigner-Negative Magnon Steady States from Incoherent Qubit Pumping

We show that incoherently pumped qubits can realize a cascaded dissipative mechanism for stabilizing Wigner-negative magnon steady states. The mechanism combines qubit pumping with dispersive magnon-number selectivity to direct the steady-state population toward selected magnon Fock states. In the single-qubit case, the single-magnon population can approach unity, accompanie...

A single-electron double quantum dot with Rashba spin-orbit interaction as a working substance for heat machines

We investigate the thermodynamic performance of a quantum Otto machine whose working substance is a single electron confined in a double quantum dot under an external magnetic field and Rashba spin-orbit interaction. The Hamiltonian is controlled by the Zeeman splitting, the interdot tunneling amplitude, and the Rashba coupling, which induces spin-flip tunneling between loca...

Emergence of Gaussian entanglement and non-Gaussianity in high-harmonic generation driven by bright squeezed light

High harmonic generation (HHG) is a highly nonlinear optical process in which radiation from a strong driving field is up-converted into its high-order harmonics. In atomic systems, this nonlinearity manifests itself through the intensity scaling of the emitted harmonics with the driving field strength. Despite the highly nonlinear nature of HHG, when the driving field is pr...

Lewis-Ermakov approach for the time-dependent two-level system

We construct an explicit Lewis-Ermakov-type dynamical invariant for time-dependent two-level systems by exploiting their algebraic correspondence with the time-dependent harmonic oscillator through the su(2) and su(1,1) algebras, which share the common complexification sl(2,C). This invariant provides a closed-form evolution operator and an exact propagator fo...

A Measurement-Like Test of Continuous Spontaneous Localization with a Reversible Nanoparticle Pointer

We propose a measurement-like interferometric test of Continuous Spontaneous Localization (CSL), in which a trapped nanoparticle acts as a reversible mesoscopic pointer rather than as the initially prepared microscopic superposition. A microscopic two-branch system applies opposite weak forces to the nanoparticle, temporarily amplifying which-branch information into branch-c...

Generalization of catability for parity-less cat states

We extend the nullifier-based certification framework of catability from parity-defined coherent cat states to parity-less Kerr cat states. Since Kerr cats cannot be distinguished by parity alone, we replace the parity component of the original nullifier with a displaced-parity operator that captures their characteristic interference structure. The resulting generalized cata...

Nonlinear Geometrizability of State-Dependent Proto-Area in Approximate Holographic Codes

State-dependent proto-area data produced by approximate recovery need not be compatible with a single local bulk metric. Using recovery maps calibrated on the code channel and held fixed along a logical-state family, we derive exact finite-resolution criteria and, near the hyperbolic disk, necessary and sufficient conditions for a regular proto-area two-jet to arise from a m...

How Many Qubits Does a Quantum Computer Need?

Guest post by Zeynep Koruturk, Dr. Kris Naudts, & Donald Harmitt of Firgun Ventures and Professor Bob Coecke of Relational Intelligence Limited Few questions in the quantum sector are asked more often, or answered more loosely, than how many qubits a useful quantum computer will require. Press releases announce systems with hundreds of qubits, then [...] The po...

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