September 1, 2026

Xanadu Unveils Technical Roadmap Targeting 1,000+ Logical Qubits by 2031Tier 2

Photonic quantum computing developer Xanadu (NASDAQ/TSX: XNDU) has released an expanded, milestone-driven technical roadmap detailing hardware performance indicators, quantum error correction (QEC) targets, and commercialization timelines through 2031. Presented during an executive briefing led by CEO Christian Weedbrook, COO Rafal Janik, and CFO Michael Trzupek, the road...

Device characterization of Si/SiGe double quantum dots using exchange oscillations in Earth's magnetic fieldTier 3

Exchange-based semiconductor qubits encompass a broad family of encodings constructed from singlet- and triplet-like spin states, several of which are compatible with operation at zero applied magnetic field. Their reliable operation requires characterization of environmental noise, residual idle interactions, and exchange-dependent decay, but this characterization often rel...

Fast Fault-Tolerant Decoders for Hypergraph Product and Lifted-Product CodesTier 3

We design low-complexity, fault-tolerant decoders for quantum low-density parity-check (QLDPC) codes with the goal of reducing decoding latency. We target two major bottlenecks of decoding under the \emph{circuit-level} noise model: (i) post-processing via order-statistics decoding (OSD), and (ii) the large number of auxiliary variable nodes commonly introduced to represent...

Protected Logical Qudits in Kitaev Quantum Double Models via Stable RepresentationsTier 3

Fault-tolerant quantum computation requires robust protection of encoded quantum information. In this work, we develop a representation-theoretic framework for constructing protected logical qudits in finite-group Kitaev quantum double models. By introducing ε-stable irreducible representations, we establish a necessary and sufficient existence criterion and deri...

Deterministic Universal Logical Gates for Finite-Energy GKP Qubits in Trapped Neutral AtomsTier 3

We present a universal logical gate set for finite-energy Gottesman-Kitaev-Preskill (GKP) qubits encoded in the harmonic motional states of trapped neutral atoms. Internal electronic states serve as ancilla for implementing state-dependent conditional displacements in phase space, enabling arbitrary single-qubit phase gates. A Transient Rydberg excitation-mediated atomic dip...

Phase-noise induced many-body interference suppression in Gaussian Boson SamplingTier 3

We develop a Heisenberg-picture tensor-network formulation of collision-free Gaussian Boson Sampling, providing a direct Fock-space expression for output probabilities in terms of experimentally accessible quantities. The resulting representation naturally recovers the Hafnian structure while revealing the decomposition of GBS probability into a phase-insensitive contributio...

Signatures of inter-sideband coherence in the resonance fluorescence spectrum of an acoustically-modulated quantum dotTier 3

We theoretically investigate the inter-sideband phase coherence within the resonance fluorescence spectrum of an acoustically modulated quantum dot using a filtered-field formalism for a Mach-Zehnder configuration. We demonstrate that geometric slant of the interferograms provides an indicator of phase coherence that is resilient to environmental white noise. Specifically, n...

Quantum Block Turbo CodesTier 3

In the early nineties, the introduction of turbo codes revolutionized classical error correction. The idea was mainly applied on two types of codes: convolutional turbo codes and turbo product codes. The first type of codes was adapted to quantum error correction which initiated the theory of quantum serial turbo codes. In this paper, we present a theory for quantum block tu...

PauLie: Fast Classification of Pauli Dynamical Lie AlgebrasTier 3

The dynamical Lie algebra (DLA) governs the controllability, expressibility, and simulation complexity of a quantum system. Explicitly computing it has been a major computational bottleneck: brute-force Lie closure scales exponentially in the number of qubits n. Many applications, however, consult only the isomorphism type of the DLA. We introduce PauLie, an open-source fr...

Trade-off between Cooling-Step Count and Geometric Implementation Cost in Non-Markovian Algorithmic CoolingTier 3

Quantum cooling is important for reliable quantum computation but involves a trade-off between cooling performance and implementation resources. Although reservoir memory can improve particular aspects of cooling performance, the associated resource cost, particularly for circuit implementation, remains insufficiently understood. Here, we investigate how reservoir memory aff...

Quantum Imaginary Time Evolution on an Infinite 1D ChainTier 3

We introduce a quantum-circuit algorithm for performing imaginary-time evolution on infinite one-dimensional lattice systems. The method uses a parameterized quantum circuit to represent a uniform matrix product state ansatz. We derive the ITE algorithm using the time-dependent variational principle and employ the quantum Lanczos algorithm to improve the ground-state energy...

Modular-Annihilator Parent Hamiltonians for Purified Gibbs States: Spectral Design and Controlled ApproximationTier 3

Purified Gibbs states provide a bridge between finite-temperature physics, dissipative dynamics, and ground-state methods. In this work, we study the exact finite sum-of-squares (SoS) construction of their parent Hamiltonians and the associated Lindbladian based on modular annihilators. Given a finite set of Hermitian generators, the corresponding modular annihilators yield...

Pasqal and KACST Partner to Advance Post-Quantum Cryptography in Saudi ArabiaTier 2

Neutral-atom quantum hardware vendor Pasqal (Nasdaq: PSQL) and Saudi Arabia’s King Abdulaziz City for Science and Technology (KACST) have signed a strategic research collaboration agreement to advance quantum technology R&D and post-quantum cryptography (PQC) readiness across the Kingdom. Executed via KACST’s National Center for Quantum Technologies (NCQT), the multi-...

Previously: 2026-08-25

Efficient measurement schemes for the Monte Carlo projective quantum eigensolverTier 3

The Monte Carlo Projective Quantum Eigensolver (MC-PQE) was recently introduced as an alternative to hybrid algorithms like the variational quantum eigensolver (VQE). By using a quantum Monte Carlo-inspired scheme for energy estimation, MC-PQE was found to decrease the required measurement cost relative to comparable conventional approaches. However, in the context of VQE, n...

Quantum Simulation of Markovian and Non-Markovian Open Quantum Dynamics in Heavy-Ion CollisionsTier 3

We present a quantum computing framework for simulating open-quantum-system approaches based on Markovian and non-Markovian dynamics, which is relevant to heavy-ion collisions. To simulate the non-Markovian evolution on quantum computers, we introduce an auxiliary two-level pseudomode that carries the memory forward and couples to both the subsystem and the residual Markovia...

Anyon Systems and Matrix Group Partner to Accelerate International Quantum Supercomputing DeploymentsTier 2

Canadian full-stack superconducting quantum hardware vendor Anyon Systems has signed a strategic partnership with KMT Technologies Ltd., a member of the international technology integration conglomerate Matrix Group. Under the agreement, KMT will act as an exclusive distributor and authorized integration partner across strategic international markets, delivering on-premis...

Atom Computing Appoints Kevin Messerle as Chief Financial OfficerTier 2

Diffraqtion Raises More Than $10M for Quantum Camera DevelopmentTier 2

Yaqumo and SCREEN Holdings Partner on NEDO Project to Build Optical Modules for Neutral-Atom QPUsTier 2

Japanese neutral-atom quantum computing startup Yaqumo Inc. (a spin-off from Kyoto University and the Institute for Molecular Science) has been selected by Japan’s New Energy and Industrial Technology Development Organization (NEDO) for a national R&D grant under the Post-5G Information and Communication Systems Infrastructure Enhancement R&D Project. Following th...

QTREX Quantum to Unveil 17,280-Line Cryogenic Interconnect Architecture at IEEE Quantum Week 2026Tier 2

Cryogenic interconnect developer QTREX Quantum Ltd. (Nasdaq: QTEX) has announced plans to publicly unveil an ultra-high-density interconnect architecture capable of supporting up to 17,280 coaxial lines per cryogenic stage inside commercial dilution refrigerators . The architecture will be demonstrated physically at IEEE Quantum Week 2026 (Booth 712) in Toronto, Canada, f...

Diraq to Deploy Eight-Qubit Silicon Quantum Computer at Equinix Sydney Data CenterTier 2

Silicon spin-qubit hardware vendor Diraq and global digital infrastructure provider Equinix, Inc. (Nasdaq: EQIX) have announced plans to deploy an eight-qubit quantum processing system inside an operational Equinix commercial data center in Sydney, Australia. Scheduled for installation completion in October 2026, the system represents the world's first silicon spin quantu...

QuantrolOx and QURECA Partner to Launch Quantum EDGE Academy for Hands-On Hardware TrainingTier 2

Quantum measurement and control software developer QuantrolOx (Espoo, Finland / Oxford, UK) has partnered with quantum education provider QURECA (Glasgow, UK) to launch the Quantum EDGE Academy. Integrated into QURECA's educational catalog, the initiative provides a flight-simulator-style software environment to train experimentalists, technicians, and hardware engineers...

Guest Post: The Quantum Industry is Both Overhyped And UnderestimatedTier 2

Size-Independent Robustness in Multipartite Bell Self-TestingTier 3

Practical robust self-testing of multipartite entanglement has so far been restricted to small-scale systems due to error bounds that degrade severely with system size. In this work, we establish multipartite self-testing with robustness independent of the size of the quantum network. We derive a fully analytic, device-independent self-testing bound for n-qubit Greenberger...

Photon-efficient quantum repeater chains via hyperentanglement-assisted purificationTier 3

Linear quantum repeater chains based on Werner-state purification (the BBPSSW protocol) and entanglement swapping (the BDCZ scheme) are fundamental to entanglement distribution in quantum networks. However, they operate under a stringent operation reliability threshold and rely on resource-intensive recurrence purification rounds, each consuming two entangled pairs to probab...

Efficient search for excitable zero-modes in constrained systemsTier 3

Kinetically constrained systems, such as those representing Rydberg atom arrays in the blockade regime, have gathered considerable attention due to the presence of atypical eigenstates in their spectrum. The latter manifests itself through the presence of quantum many-body scars as well as unusually large zero-mode (ZM) subspaces which contain analytically tractable eigensta...

Engineering multi-photon dissipation with a dc-voltage-biased Josephson junctionTier 3

Multi-photon dissipation -- a key resource for bosonic qubits -- is usually realized by parametrically pumping a Josephson coupler at the cost of spurious nonlinear terms. Here we instead engineer it using a dc-voltage-biased SQUID, such that these parasitic terms average out. We activate the conversion of one, two, or four photons of a high-Q mode into a single photon of a...

"Train classical, deploy quantum" requires rethinking generalizationTier 3

Generative models have become central across science and industry, from image and text synthesis to the design of molecules and materials. Quantum generative models are considered one of the most promising applications for quantum computers, since a quantum circuit naturally produces samples from the distribution it encodes, and for suitable circuits that distribution is bel...

Tunable Exceptional Points for Quantum Sensing in a Spin--Orbit-Angular-Momentum Coupled BECTier 3

Exceptional points (EPs) can induce strongly amplified responses to weak perturbations, but enhanced spectral sensitivity in conventional non-Hermitian systems does not necessarily translate into improved quantum-limited sensing because of the associated gain and loss noise. Here, we investigate a tunable EP sensing platform based on the intrinsic non-Hermitian Bogoliubov dy...

Rotating-wave approximation for spin-boson models with structured fieldsTier 3

We derive state-dependent bounds on the difference between two quantum evolutions generated by unbounded Hamiltonians sharing a common form domain. The main technical tool is a second integration by parts, performed at the level of sesquilinear forms rather than at the operator level, which removes the need for a common invariant operator domain. The resulting estimate invol...

Deterministic Minimum-Output-Entropy Nonadditivity via Haagerup's Inequality and Near-Free Permutation RepresentationsTier 3

We give a deterministic realization of the finite-dimensional quadratic certificate underlying Collins's mixed-unitary proof of minimum-output-entropy nonadditivity. For every fixed integer K≥2 and rational η>0 satisfying log K>2(3+η)^2, a deterministic polynomial-time algorithm, for every sufficiently large target size N, outputs K permutations on $N'=N+o_{K,η...

Boundary Quantum Knizhnik-Zamolodchikov Equations and Integrability of Quantum Field Theories with Time-Dependent Bulk and Boundary Coupling StrengthsTier 3

The generalized Bethe ansatz framework formulated in [P. R. Pasnoori, Phys. Rev. B 112, L060409 (2025)] provides a unified framework to find exact solutions to quantum many-body systems with time-dependent coupling strengths with periodic boundary conditions. In this work we extend this framework to the case of open boundary conditions where in addition to the time-dependent...

Work Extraction Across a Thermodynamic Hierarchy in Quantum Many-Body SystemsTier 3

Thermodynamics is operational in the sense that the very concept of thermal equilibrium depends crucially on the choice of observables, while the amount of extractable work is defined relative to the allowed operations. Here we show that isolated quantum many-body states admit a thermodynamic hierarchical structure of observables and allowed operations, where the same state...

On the relaxation problem in statistical mechanicsTier 3

We reformulate the relaxation problem in statistical mechanics by making explicit what are the \emph{operational} objects subject to relaxation: the local time statistics of the recorded signal Z(t). These local time statistics are simply the estimated histograms of observations {Z(t_i)}_(i=1)^M performed at uniformly random times {t_i}_(i=1)^M by a clockless obser...

Well-conditioned iterative methods for large open quantum systemsTier 3

Markovian open quantum systems are well modeled by the Lindblad Master Equation (ME) d/(d t) ρ_t = L ρ_t, where L is a linear (super-)operator and ρ_t is the system state, a positive matrix. When designing or characterizing a quantum system, one is usually interested in the steady state ρ_∞ (such that L ρ_i...

Metrological quantum-to-classical crossover in the volume of a noisy quasiperiodic latticeTier 3

Localization-delocalization transitions have recently been proposed for building a class of efficient quantum many-body critical sensors. This work scrutinizes metrological performances of such devices by focusing on the Aubry-André-Harper model that supports a localization-delocalization transition at finite strength of the onsite potential. We identify a metrological quant...

Chiral Color Ice: Exact Local Handedness Constraints and Möbius Zero Modes in Frustrated MagnetsTier 3

Local constraints govern the low-energy physics of frustrated matter, but familiar ice-type rules constrain flux-like quantities and are insensitive to handedness. Here we show that handedness itself can be imposed as an exact local quantum constraint without selecting an axis in spin space. We construct positive-semidefinite, SU(2)-invariant parent Hamiltonians whose comple...

Cycle-Structure Generating Functions for Special Breakpoint GraphsTier 3

Breakpoint graphs originate in comparative genomics, where their alternating cycles encode relationships between genomes. We study a constrained class of three-colored breakpoint graphs associated with permutations and develop cycle-refined generating functions for two extremal families. These families have a natural topological interpretation: their canonical surfaces are,...

A Truncated MajoranaTier 3

We investigate the quantum field dynamics of truncating a Majorana wave packet via a time-dependent channel shutter. Modeling truncation as a controlled modification of chiral propagation rather than a literal spatial cut, we analyze a 1+1D massless Majorana field subjected to a time-dependent rotation between its chiral components. We demonstrate that this protocol manife...

Flatness-Preserving OperationsTier 3

A quantum state is called flat if it is proportional to a projector. There has been recent interest in studying antiflatness, the property of diverging from flat states, and establishing a resource theory for it. Identifying the free operations (the Flatness-Preserving Operations (FPOs)) remained an open problem. For this purpose, we first discuss Orthogonality-Preserving Op...

Entanglement-enabled Criticality in One-dimensional Quantum Contact ProcessTier 3

The contact process is a paradigmatic example of nonequilibrium dynamics, with broad applications ranging from chemistry to sociology. Its quantum counterpart, the quantum contact process (QCP), extends the classical model to include coherent processes. Despite sustained interest, the nature of the transition in the one-dimensional (1D) QCP remains debatable. Here, combining...

Gate-Efficient Implementation of the Query-Optimal Time-Dependent Hamiltonian SimulationTier 3

The query-optimal algorithm of [CGWZ26] for general time-dependent Hamiltonian simulation uses q = O( αT + (log(1/ε))/(log(e + log(1/ε)/(αT) )) ) queries to HAMmbox-T within ε error for a Lipschitz-continuous time-dependent Hamiltonian H(t) on [0,T] satisfying lVertH(t)rVertl...

Mass-gap functional determinant approach for mobile Fermi polaronsTier 3

We extend the functional determinant approach (FDA), previously restricted to static impurities, to the case of finite-mass impurities by using the mass-gap description of Fermi polarons [Phys. Rev. Lett. 135, 193401 (2025)]. The quadratic structure of the mass-gap model enables the exact evaluation of many-body spectra and Ramsey dynamics for mobile impurities. We show that...

Quantum non-local games: Quantum relations, projection lattices and rule operatorsTier 3

Quantum non-local games with quantum inputs or outputs have been formulated in several different languages, including rank-one and quantum XOR games, support maps between projection lattices, probabilistic quantum hypergraphs, and Frobenius-algebraic rule operators on finite quantum sets. We give a unified operator-algebraic comparison of these models by assigning to each ru...

Cross-Spectral Reservoir Correlations as a Resource for Finite-Time Quantum Otto EnginesTier 3

We investigate the thermodynamic consequences of longitudinal-transverse cross-spectral reservoir correlations in a finite-time quantum Otto engine with a two-level working medium. Each reservoir couples through excitation-relaxation and dephasing channels whose fluctuations are characterized by a Hermitian positive-semidefinite spectral-density matrix, with the off-diagonal...

First-principle predictions of fragmentation functions via quantum computingTier 3

We report on an algorithm to compute fragmentation functions from the first principles Quantum Chromodynamics (QCD) Hamiltonian quantized in Light-Front Gauge, opening a path for digital quantum computers to calculate these longitudinal jet-structure observables. Simulating the behaviour of such computers on a classical cluster (which is memory-limited to about 30 qubits, gi...

Marginal spectral distributions on regular bipartite unitary orbitsTier 3

Fix the spectrum of a bipartite density matrix and randomize its eigenbasis according to Haar measure. We study the probability distributions induced on the spectra of the two marginal states. For arbitrary subsystem dimensions m and n, the joint characteristic function of the reduced density matrices is expressed as a Harish-Chandra-Itzykson-Zuber integral whose externa...

Exact quantum splitting and the structure of finite algebrasTier 3

Berlekamp's algorithm factors a squarefree polynomial f∈F_q[x] by deterministic linear algebra, reducing the problem to splitting an explicit commutative algebra BcongF_q^r into its r simple factors. For large odd q, the standard efficient splitting step is randomized, while known derandomizations are conditional on the Extended Riemann Hypothesi...

Scalar Spin Chirality from Dissipative Pumping and Lamb Shift PrecessionTier 3

Circulating currents in triangular triple quantum dots reverse repeatedly with bias even at zero magnetic flux and for a real Hamiltonian, a phenomenon whose origin has remained unclear. We show that dissipative tunneling prepares an orbital pseudospin, while virtual charge fluctuations generate a noncollinear Lamb field that rotates it toward the chiral direction. Bias chan...

Quantum-interference metrology of dissipative Kerr solitonsTier 3

Dissipative Kerr solitons in optical microresonators underpin chip-scale frequency combs with applications ranging from coherent telecommunications to precision spectroscopy. Yet the characterization of their intrinsic femtosecond temporal structure remains challenging, as the low pulse energy and broad spectral bandwidth necessitate optical amplification and careful dispers...

Indirect stabilization of N -level quantum systemsTier 3

We study the stabilizability of a N -level quantum systems using an indirect control ar- chitecture mediated by a noisy ancilla. After outlining the general theoretical framework for arbitrary N , we focus on the two-level case (N = 2), for which we derive a complete set of necessary and sufficient conditions for asymptotic stability. Finally, we illustrate the analyti- cal...

Best Annealing Path of Quantum Annealing via Efficient Adiabatic Phase TransitionTier 3

Quantum Annealing (QA) has already put into practical use and considered useful for solving many social issues, such as reduction of traffic congestion and delivery optimization. But in QA, when the energy difference between the ground state and the first excited state is small, the transition probability between them increases. Therefore, in order to decrease the transition...

Efficient biphoton generation by a waveguide-coupled single atomTier 3

A single atom undergoing spontaneous four-wave mixing near a chiral waveguide can efficiently channel an emitted Stokes-anti-Stokes photon pair into two tightly confined waveguide modes, yielding thus enhanced biphoton generation without requiring loss suppression or stringent phase matching. We develop a perturbative treatment, valid for a four-level atomic system under exp...

Diffraqtion Caps Pre-Seed Round at $10M+ with Strategic Backing from Lockheed Martin and Presidio VenturesTier 2

Quantum-enabled optical sensing startup Diffraqtion has closed an expanded pre-seed financing round totaling over $10 million. The round welcomed strategic investments from Lockheed Martin Ventures and Presidio Ventures (the venture capital arm of Sumitomo Corporation), joining existing backers including Ground State Ventures, SBI US Gateway Fund (with Plug and Play), Col...

Podcast with Steve Orrin, Chief Technology Officer for Intel FederalTier 2

Yuval Boger speaks with Steve Orrin, Intel’s Federal Chief Technologist, about the sweeping post-quantum cryptography mandates confronting U.S. government agencies and their supply chains. Orrin breaks down the 2030-2031 migration deadlines, the January 2027 acquisition requirement for national security systems, and why a standard Windows laptop can contain 20,000 crypto...

Quantum-Classical Software Tests New Approach to Protein FoldingTier 2

Quantum-Tunnelling Field-Effect Transistor Designed to Overcome Integrated-Circuit Chip Development BarriersTier 2

Congressman Langworthy Introduces American Quantum Competitiveness ActTier 2

Quantum information in neutron-proton scattering from the M matrixTier 3

We study quantum-information aspects of neutron--proton scattering in the spin-space M-matrix framework. Four representative classes of input states are considered, namely diagonal mixed states, separable pure states, general two-qubit pure states, and a special Schmidt-like entangled subclass. For each class, ensemble-averaged output mutual information, reduced-state line...

Unconditional Certified Randomness without StructureTier 3

We obtain a certified randomness protocol in the quantum random oracle model. The protocol is non-interactive and publicly verifiable with a classical verifier, and is based on Yamakawa and Zhandry's proof of quantumness [JACM'24]. We prove unconditional security of this protocol against adversaries making subexponentially-many adaptive quantum queries to the random oracle....

Previously: 2026-08-26

Constrained minimax approximation for quantum signal processingTier 3

Quantum signal processing (QSP) provides a simple and efficient framework for implementing polynomial transformations using quantum circuits. Its classical design stage leads to a constrained minimax approximation problem: find a polynomial of prescribed parity that approximates a target function uniformly on a fitting set while remaining bounded in magnitude by one on the d...