October 16, 2026

Remote Gottesman-Kitaev-Preskill Entanglement Generation between Trapped IonsTier 3

Distributing entanglement directly between error-corrected logical qubits is an important capability for scalable quantum networks. We propose a heralded protocol for generating remote entanglement between Gottesman--Kitaev--Preskill qubits encoded in the motional modes of spatially separated trapped ions, using the internal electronic states to interface the motional qubits...

Stability of Quantum LDPC States under Local Pauli NoiseTier 3

Quantum low-density parity-check (qLDPC) codes have a canonical mixed state---the normalized projector onto the code space---that lies at the intersection of quantum error correction and quantum many-body physics, yet the stability of its information-theoretic structure under local noise remains poorly understood. Recent progress on mixed-state phases of matter has identifie...

SynDebug: A Framework to Debug Logic Bugs in Fault-Tolerant Quantum Computing ProgramsTier 3

Fault-tolerant quantum computing (FTQC) introduces substantial systems-level complexity through quantum error correction (QEC), making debugging FTQC programs challenging. Existing quantum debugging approaches primarily target logical-level circuits and do not naturally support debugging within realistic FTQC execution flows. We present SynDebug, the first systems-level debu...

Programmable all-to-all entangling gates for cavity-coupled atomsTier 3

Fault tolerant quantum computers greatly benefit from having both high fidelity entangling gates and a non-local qubit connectivity. However, most entangling gates for neutral atoms are local, requiring separated atoms to be moved using optical tweezers to yield entanglement between them. Here, we design a high fidelity Mølmer Sørensen-like entangling gate between neutral at...

Energetics of Fault-Tolerant Spin-Qubit Quantum ComputationTier 3

Semiconductor spin qubits offer a promising route to compact and scalable quantum computers, combining long coherence times in isotopically purified silicon with compatibility with semiconductor manufacturing. Beyond computational speedup, their energy efficiency is an important consideration for future large-scale systems. We evaluate the power and energy requirements of a...

Patchwork: automated lattice surgery and space-time partitioning for real-time decodingTier 3

We introduce patchwork, a lattice-surgery compiler for arbitrary multi-qubit Pauli measurements on a prescribed narrow-corridor two-dimensional surface-code layout. Systematic geometric rules simplify stabilizer placement and gate scheduling, including for logical Y measurements implemented using twist defects. We introduce measurement circuits and schedules that, together...

Bubble-Sort Exchange Networks: Symmetry Selection Rules and Language-Model Distillation on Exchange-Only Spin ChainsTier 3

On a chain of exchange-coupled quantum dots a Heisenberg exchange pulse of area pi is a SWAP, so the parallel bubble-sort SWAP network of superconducting chains is native to exchange-only (EO) spin qubits, and any other pulse area fuses routing with an entangling interaction. We build a variational "bubble-sort exchange network" (odd-even transposition, one parameter per pul...

Looking Beyond Visibility: Resolving the Temporal Structure of Continuous-Wave Four-Photon Hong-Ou-Mandel InterferenceTier 3

Hong-Ou-Mandel interference underpins many photonic quantum information protocols and is commonly characterized by a single visibility parameter. This quantity is typically obtained by averaging over a fixed coincidence window, thereby discarding details of the underlying temporal structure that are critical in continuous-wave processes. Four-photon interference with continu...

Loss-independent time-delay estimation via Hong-Ou-Mandel photon bunching detectionTier 3

In this work we study the application of two-photon correlated quantum states for high-precision time estimation. To achieve this, photon pairs were fed into a Hong-Ou-Mandel polarization interferometer to generate N00N entangled states with N = 2. Two- and four-detector schemes were considered, and the achievable time estimation precision of each was studied, with particu...

Germany Issues Joint Federal PQC Migration Guidelines to Align with EU Post-Quantum RoadmapTier 2

Germany has released national guidelines for migrating to Post-Quantum Cryptography (PQC), aligning with the EU's roadmap. The strategy, driven by advancements in AI and threats to classical encryption, outlines a three-phase migration timeline, prioritizing high-risk systems by 2030 and aiming for full migration by 2035. This initiative mandates hybrid cryptographic mech...

Quantum control of solid state qubits via Reinforcement LearningTier 3

The use of reinforcement learning (RL) in the design of quantum control strategies for pulse level control of NISQ era quantum devices is attracting growing interest. Model-free RL, not requiring preexisting knowledge of the physical system, acts as a black-box optimization tool well suited for noisy devices. In this work, we provide a simulation-based analysis of the perfor...

Synergistic charging of a quantum battery via Dzyaloshinskii-Moriya interaction and non-Markovian noiseTier 3

Protecting quantum batteries from environmental noise remains a challenge. Using exact Burshtein-Kubo equations, we study a two-spin quantum battery with Dzyaloshinskii-Moriya (DM) coupling under indepen dent local longitudinal random telegraph noise (RTN). At a fixed effective noise scale, the DM-assisted slow switching protocol yields a superadditive transient ergotropy ga...

Same Spectrum, Harder First-Order Training: Phase-Locking in Single- versus Multi-Qubit Re-Uploading CircuitsTier 3

Angle-encoded variational quantum circuits implement truncated Fourier series. For one-dimensional inputs, a single-qubit re-uploading (serial) circuit represents every function that a multi-qubit circuit with the same encoding budget E can; we find that this exchange of width for depth is not free in first-order training. Because its state lives on the Bloch sphere, all p...

Correlation between normal character and Raman intensities of isotopologues of carbon dioxideTier 3

Previous studies on the vibrational structure of carbon dioxide isotopologues have revealed a correlation between the strength of Fermi interactions and a recently defined normal-mode parameter. In this contribution, we investigate how the Raman intensities of the most intense bands evolve across the complete series of carbon dioxide isotopologues at room temperature. To thi...

Jianmu-Q: Bridging Quantum Field Theory and Quantum Hardware with AI AgentsTier 3

Quantum computing offers a promising approach to non-perturbative simulations of quantum field theories, particularly for real-time dynamics and systems affected by the sign problem. Yet translating continuum field theories into quantum computations remains a challenging interdisciplinary task. Here we introduce \texttt{Jianmu-Q}, a multi-agent framework that transforms natu...

Three-axis Active Magnetic Compensation with Spatial Feedforward Matrix Decoupling and Hysteresis PI Regulation for Suppressing Zeeman Decoherence of Cold Atom Quantum MemoriesTier 3

Cold-atom quantum memories require a near-zero magnetic environment (residual field <1 microtesla) to mitigate Zeeman decoherence. Conventional three-axis active compensation suffers from inter-coil crosstalk and geomagnetic drift, which degrade the uniformity and long-term stability of the zero-field region. To address this, we propose a spatiotemporally cooperative feedbac...

Realization Divergence in Multi-Provider Quantum Computing: A Pre-Registered Study of What Survives MeasurementTier 3

Quantum programs pass through compilers, transpilers and vendor services before execution. However, the distance between what was written and what runs is rarely measured. We call this distance realization divergence: the observable difference in how an identical source circuit is realized and behaves across quantum software stacks. We report a hardware study across three ve...

Classiq Partners with FreeYa Mind Campus to Launch Quantum Applications Hub in RomaniaTier 2

Classiq has partnered with FreeYa Mind Campus to open a Quantum Applications Hub in Iași, Romania, which will serve as Classiq's regional headquarters. This hub integrates Classiq's quantum software platform with the campus's IBM Quantum System Two. The collaboration aims to drive quantum software development, education, and enterprise projects across Eastern Europe. ...

Stony Brook Quantum Memory Named to TIME’s Best Inventions of 2026Tier 2

Insider Brief PRESS RELEASE — A quantum technology invented at the State University of New York (SUNY) at Stony Brook (Stony Brook University) is earning international recognition. Qunnect’s Qu-MEM, a commercial room-temperature quantum memory device developed from Stony Brook-patented technology, has been named to TIME’s Best Inventions of 2026 in the Experimental cat...

Sweden Joins European Quantum and AI Skills AcademiesTier 2

Insider Brief PRESS RELEASE — As quantum technologies transition from the laboratory to the market, the demand for a highly skilled workforce has never been greater. To meet this challenge, EQA has officially launched to establish a comprehensive, pan-European ecosystem for quantum education and training. Nordita, the Nordic Institute for Theoretical Physics in Stockho...

IonQ and University of Cambridge Open Quantum Innovation CentreTier 2

Insider Brief PRESS RELEASE — IonQ (NYSE: IONQ), the world’s leading full-stack quantum platform and foundry, and the University of Cambridge have announced the opening of the first-ever university-based IonQ Quantum Innovation Centre. The Centre is located at the Ray Dolby Centre, the new home of the University’s Cavendish Laboratory. This initiative bring...

Quantum Alliance Launches to Set Post-Quantum Standards for BlockchainsTier 2

Insider Brief PRESS RELEASE — CEOs, CTOs, and founders from nine blockchain organizations today launched the Quantum Alliance, an open standards body that will set the criteria for judging quantum-resistance claims in blockchain and create standards for compatibility between the networks as they migrate. The Alliance will define what post-quantum readiness means for bl...

Discovering state-of-the-art quantum circuits with large language modelsTier 3

Significant efforts are currently being directed toward the implementation of large-scale quantum information processors, but realizing useful quantum advantage also requires the development of efficient quantum algorithms. While for many practical problems the dominant resource costs are associated with a small set of computational primitives, optimizing them in the quantum...

Classical Capacity of Single-Mode Bosonic Gaussian ChannelsTier 3

The classical capacity of a noisy optical channel is the maximum rate at which information can be transmitted reliably, given a constraint on the mean input energy. For the ubiquitous bosonic Gaussian channels, which include standard models of loss and noise in fibre and free-space optical links, determining this rate requires addressing whether entanglement between channel...

Adding Temperature to the Adiabatic Connection: Hybrid Functionals for Static and Dynamic CorrelationTier 3

Capturing static and dynamic electron correlation simultaneously at manageable computational cost remains a key challenge in electronic structure theory. Motivated by the recurring role of effective temperature in self-consistent field methods we extend the adiabatic connection mechanism from density functional theory to include a temperature dimension. This gives rise to th...

Constrained dissipation and the lifetime of quantum many-body scarsTier 3

We investigate the fate of quantum many-body scars in the PXP model subject to Markovian dissipation. We show that when local jump operators respect the same symmetries of the Hamiltonian the full Liouvillian spectrum displays a tower of states with properties analogous to standard quantum scars: large overlaps with Néel states and equally spaced gaps in the imaginary part o...

Efficient quantum simulation of unitary gates based on atomic ensemblesTier 3

We develop a technique to perform efficient unitary time evolution of a general spin Hamiltonian based on the system with identical qubits, as naturally realized by permutation symmetric atomic ensembles. We employ Cartan decomposition method to the associated Hamiltonian Lie algebra and construct the symmetry adapted generators to implement unitary operator of the ensemble...

Putting a Temperature on Electron CorrelationTier 3

It is common wisdom that a better understanding of how to quantify electron correlation should lead to more efficient treatments of the correlation problem. Here, we not only substantiate this view but turn it into a concrete, systematic framework for ground states. Since prominent correlation measures such as the nonfreeness depend only on the one-particle reduced density m...

Generalized m-body mean-field projections for classical simulation of d-dimensional Heisenberg-picture dynamicsTier 3

Classical simulation of quantum many-body dynamics is challenged by the rapid growth of operator complexity, particularly in higher dimensions where tensor-network methods become increasingly demanding. We develop state-adapted Pauli-weight propagation based on generalized m-body mean-field projections, which compress many-body observables into optimal low-body representat...

Energetic channels in finite many-body quantum chargingTier 3

We examine how a finite many-body system can function as an effective charger for a single-qubit quantum battery, using the Lipkin-Meshkov-Glick model as a paradigmatic setting. As our figure of merit, we consider the battery ergotropy while explicitly resolving the energetic flows across the composite system. In the absence of intra-charger interactions, we show that the ge...

Thermal activation of photon catalysis in difference-intensity Mach-Zehnder interferometry with squeezed thermal lightTier 3

Realistic non-Gaussian operations, which can be implemented by mixing a nonclassical Gaussian state with a Fock state at a beam splitter and then heralding on a photon-number-resolving detector, are known to improve phase estimation in a Mach-Zehnder interferometer. The existing studies have considered the single-mode squeezed vacuum for difference-intensity and parity detec...

A complete classification of perfect state transfer in Grover walks on abelian Cayley graphsTier 3

We completely classify connected Cayley graphs over finite abelian groups that exhibit perfect state transfer in Grover walks. First, we show that a Cayley graph over any finite group exhibiting perfect state transfer has valency $1$, $2$, or $4$. For valency $4$, we prove that an abelian Cayley graph Cay(Γ,S) exhibits perfect state transfer if and only if $...

Opinion bubbles in the quantum Buridan's ass problemTier 3

The quantum Buridan's ass problem concerns a network of interconnected nodes in which transitions between the nodes are governed by the laws of quantum mechanics. In such situations interference between probability amplitudes plays a key role in determining whether the probability of leaving the initial node is large or small and also the speed at which the associated transi...

Hybrid Quantum-Classical Optimization for Emergency-Priority Traffic Signal ControlTier 3

Emergency-priority traffic signal control requires reducing emergency-vehicle delay while limiting disruption to ordinary traffic. This work investigates a finite-horizon QUBO formulation and compares Exact QUBO optimization, QAOA, CVaR-QAOA, a quantum machine-learning policy, fixed-time control, and max-pressure control in a three-intersection corridor. The study evaluates...

One generation of the Standard Model as a quantum error-correcting codeTier 3

Together with a right-handed neutrino, the fermions of one generation of the Standard Model are labelled by five bits, a combinatorial structure tied to anomaly cancellation. We make this precise. Anomaly cancellation is the vanishing of a cubic form, the defining property of triorthogonal codes, the quantum error-correcting codes behind magic state distillation. Removing th...

Controlled-Memory Identification with Shared Generators: Dimension--Horizon Tradeoffs and Quantum--Classical SeparationTier 3

We determine the finite-horizon identification limits of a d-dimensional memory when the control interface is restricted to four shared, time-homogeneous generators. A writer encodes a message by applying a prefix word to a common root state. The verifier then applies a candidate-dependent query word followed by a shared terminal binary test, with each word of length at...

Local finite rate semi device independent randomness expansion from quantum contextualityTier 3

Finite rate randomness expansion (RE) which is secure against quantum adversaries is a crucial information processing task which is well studied in the case of two non-communicating parties sharing Bell non-local correlations in a device independent manner. In this paper we show that contextual correlations with only a single localized party are sufficient for RE in a semi-d...

Operator-Space Entanglement Entropy in Random Fermionic Gaussian DynamicsTier 3

We study the von Neumann operator-space entanglement entropy (OSEE) of initial product operators evolved under random gaussian dynamics, as modeled by a Brownian SYK_2 model. By exploiting a mapping to a domain-wall melting problem, we derive an exact expression for the time-dependent bipartite OSEE in the thermodynamic limit, and obtain an analytic characterization of the...

Size-Dependent High-Order Harmonic Generation from Linear Carbon-Chain Molecules in Linearly Polarized Laser FieldsTier 3

High-order harmonic generation from molecules is highly sensitive to molecular geometry and strong-field electron dynamics, providing a powerful route for probing and controlling ultrafast processes in extended systems. In this work, we systematically investigate the influence of molecular chain length on HHG from linear carbon-chain molecules C_2H_2, C_6H_2, and C$_...

Quantum instanton approach to metastable collective spin systems: Numerical implementation and applicationsTier 3

Driven-dissipative collective spin systems can host several long-lived metastable states; rare switching between them governs slow relaxation and first-order dissipative phase transitions associated with changes in the dominant stationary state. In the companion Letter [arXiv:2604.15091], we introduced a quantum instanton framework based on exact quasiprobability dynamics to...

Theory of Dispersion and Exchange Interactions Subjected to Surface Roughness in Application to Signal Transmission through a NanoswitchTier 3

We present the theoretical description of a resistive nanoswitch designated for a change-over between the two operation modes by calculating the electri elastic, dispersion (van der Waals and Casimir), and also exchange repulsive forces in its configuration with an account of surface roughness. The dispersion forces are described by means of the Lifshitz theory and, at the s...

Finite-size geometric crossover toward fragmentation of the potential energy shell in the quantum random energy modelTier 3

The quantum random energy model (QREM) is a paradigmatic model for studying delocalization-localization transitions at finite energy density in Fock space. In the computational basis, its diagonal energies are independent Gaussian random variables, in contrast to the correlated energies of local interacting models such as the disordered XXZ chain. In this work, we construct...

Driving the cooling process of a quantum system via classical noiseTier 3

It is known that under particular hypotheses anomalous thermalization processes can occur, such as the Mpemba effect, consisting in a faster cooling down when the system is prepared in a hotter initial condition, thus making convenient to warm up the system before the freezing process in order to make it freeze in a shorter time. It is shown here that the action of a Markovi...

Manufacturing Announcements Can Influence Patentability Challenges: What Quantum Computing Companies Should KnowTier 2

Guest post by Sarah Schlotter and Adam R. Wichman describe how the U.S. Patent Office may treat domestic manufacturing as a factor affecting when it will hear a challenge to the patentability of an issued patent claim. The article goes on to recommend best practices for quantum companies to work with this.

Google Demonstrates Method to Cut Errors in Quantum Computing’s ‘Magic States’Tier 2

Insider Brief Google researchers reduced errors in a crucial quantum computing resource about 40-fold, demonstrating a method that could lower the hardware demands of useful, error-corrected machines. The experiment, published in Science, showed that a technique called magic-state cultivation works on Google’s Willow processor, according to a Google Quantum AI blog post writ...

SEALSQ Reports 65% Revenue Growth in First Nine Months of 2026Tier 2

Insider Brief PRESS RELEASE — SEALSQ Corp (NASDAQ: LAES) (“SEALSQ” or “Company”), a company that focuses on developing and selling Semiconductors, PKI, and Post-Quantum technology hardware and software products, today announced its preliminary unaudited financial metrics for the nine-month period ended September 30, 2026 (“9M 2026”),...

Operational Limits of Gravity-Mediated EntanglementTier 3

Tests of gravity-mediated entanglement aim to determine whether two massive objects in spatial superposition can become entangled through their mutual gravitational interaction. In an ideal model, the two objects are often treated as pointlike branches, but real wave packets have a finite width and are also exposed to dephasing and residual non-gravitational forces. We study...