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• Superconducting Qubit Experiment Shows Postselection Breaks Linearity

  A superconducting transmon experiment finds nonlinear evolution in a subset of quantum measurement histories selected for having no quantum jumps. The full three-level system, counted without that filtering, retains linear evolution.

• HKMA Launches Post-Quantum Toolkit as Banks Lag on Readiness

  The Hong Kong Monetary Authority announced a post-quantum cryptography toolkit on November 2, while a July survey found that 32% of respondent banks had not begun transition work. The HKMA says the toolkit offers a framework and practical tools for banks’ transition; the survey’s first readiness score was 2.3 out of 10.

• IBM Quantum Drew 65 of 80 Teams in Japan’s NEDO Challenge

  IBM says 65 of the 80 teams in Japan’s first-season NEDO Quantum Challenge selected its quantum platform, and all nine prize-winning teams used IBM hardware during their research. Six winners used IBM systems exclusively, while one top-scoring drug-discovery project produced its final results by simulation.

• Canada Joins EuroHPC, Set to Gain Access to European Computing Resources

  Canada became a Participating State in EuroHPC at the EU–Canada Summit on October 30, 2026, and will be able to access European high-performance computing, AI and quantum resources. Prime Minister Mark Carney discussed JUPITER in a separate speech passage about proposed Canadian associate membership in the EU.

• Stuttgart Team Runs Quantum-Dot QKD for 19 Hours on Campus Fibre

  A University of Stuttgart team reports entanglement-based quantum key distribution over 1.59 km of deployed campus fibre. The 19-hour test produced 14.2 megabits of secure key using photons frequency-converted from a quantum dot.

• Five Inputs Can Reverse Bravyi–Kitaev Distillation

  A theoretical study finds that correlations can make a five-to-one Bravyi–Kitaev protocol reduce fidelity even when every input exceeds the independent-state threshold. Its neutral-atom model links that reversal to higher-order correlations and examines how block spacing and phase control affect them.

• Electron Diffraction Tracks Tunable Decoherence Near Gold

  A gold-plated microchannel lets researchers vary how strongly 1.67-keV electrons decohere near a metal surface. Their diffraction measurements show fringe visibility falling to 30–60% and match a model of quantum Brownian motion.

• Menczel and Brandner Set a New Test for Driven Quantum Relaxation

  Paul Menczel and Kay Brandner derive sufficient algebraic conditions for open quantum systems to lose dependence on their initial states. For periodic driving, their criterion requires a connectivity condition at one instant and continuity of the generator over a neighboring time interval.

• QMatter Team Runs 52-Qubit Chemistry in a Million-Atom Protein Model

  A preprint describes a hybrid simulation of ADGRG1 autoproteolysis in a model containing 1,173,254 atoms, with quantum calculations focused on the reaction site. Its reported barriers closely match a classical benchmark, while the authors note that the correlated calculations used structures from a density-functional reaction pathway.

• IBM Processor Measures Entanglement Under Stochastic Resetting

  Researchers compared entropy and concurrence in a quantum system subject to stochastic resetting, combining theoretical calculations with measurements on an IBM superconducting processor. The entropy measures closely followed noiseless predictions, while measured concurrence was lower across most of the tested range.

• Wei and Pang Develop Adaptive Control for Multi-Parameter Sensing

  Qifei Wei and Shengshi Pang propose an adaptive Hamiltonian-control strategy for estimating several parameters in two-dimensional quantum systems. Their analysis uses an extended system and feedback between measurement rounds to approach optimal precision within a finite factor.

• Szalay Adds a W-Entanglement Measure for Three Qubits

  Szilárd Szalay’s paper in Quantum introduces a polynomial measure for W-type entanglement in pure three-qubit states. The measure, ω, sits between bipartite concurrence and the three-tangle in the paper’s ordering of entanglement measures.

• Naceur, Wang and Colleagues Certify Quantum Optimization Bounds

  A paper in Quantum presents a method for converting approximate semidefinite-program results into exact certificates for bounds in quantum theory. The authors test it on Bell inequalities and quantum many-body systems, including a Heisenberg spin chain.

• Fraunhofer IAF Demonstrates 100% Contrast in Diamond Magnetometer

  Fraunhofer IAF researchers demonstrated a diamond-based laser-threshold magnetometer that can switch its laser output off at magnetic resonance, producing 100% optical contrast. The prototype reports a photon-shot-noise-limited sensitivity below 400 fT/√Hz in a vector configuration, while its highest sensitivity and widest dynamic range come from different operating conditions.

• Ono and Shiozaki Map Superconductor Topology in 159 Space Groups

  Seishiro Ono and Ken Shiozaki present a method for constructing topological invariants using the Atiyah-Hirzebruch spectral sequence. Applied to time-reversal-symmetric spinful superconductors with conventional pairing, their invariants completely characterize K groups in 159 space groups.

• Quantum Art Maps Wave Solvers Around the Condition-Number Bottleneck

  A September preprint describes a quantum algorithm that prepares states on the resonant manifold used to model wave propagation, rather than relying on direct Fourier-space preparation that the authors say becomes inefficient. Quantum Art announced the research on October 26, saying the approach could extend beyond electromagnetic waves to fields such as sound and seismic modeling.

• Rydberg-Atom Receiver Shows 210 MHz Bandwidth—with a Caveat

  A Rydberg-atom receiver demonstrated a 210 MHz frequency span using a microwave frequency comb and a position-dependent Stark field. The full-band measurements used one vapor cell at a time; a separate two-cell test showed reception across part of the span.

• Pandora Compiles a 7.7-Billion-Gate Quantum Circuit

  The Pandora software compiled a 100-by-100 Fermi–Hubbard instance into roughly 7.7 billion Clifford+T gates, according to its authors. Their paper also describes how the tool stores and rewrites circuits and reports tests of multithreading, partitioning and circuit-rewrite performance.

• IonQ Gets $7.5M AFRL Phase 2 for Quantum Networking

  IonQ says a $7.5 million Phase 2 award from the Air Force Research Laboratory will expand its Rome, New York, quantum network with optical links, converter modules and upgraded control software. The award was included in a previously announced $21.1 million collaboration, and the company describes the new equipment as planned upgrades rather than a completed deployment.

• SLAC Team Finds Direct Evidence of Altermagnetism in MnTe

  A SLAC-led team detected a chiral magnetic structure in manganese telluride, providing direct evidence that the material is an altermagnet. The result could inform future spintronics research, though the experiment did not demonstrate a device.

• ERPA Cuts VQE Energy Errors by Orders of Magnitude

  A new study applies extended random phase approximation to noisy VQE measurements of water and cyclobutadiene on IBM quantum hardware. The method sharply reduces energy errors, but depends on a classical estimate of the one-particle density matrix and still shows systematic bias.

• Columbia Team Finds Trapped Electron Waves in a 2D Metal

  A Science paper reports two electron states trapped near defects in the two-dimensional metal Pd5AlI2. The states stay localized inside a continuum of mobile electrons through interference in the material’s lattice.

• UChicago Model Finds Hidden Energy Loss in Silicon-Carbide Defects

  A University of Chicago team developed a computational framework that models internal conversion in optically active spin defects. Applied to a silicon-carbide divacancy, it identified a previously overlooked contribution to the defect’s triplet excited-state lifetime.

• IIT Patna Team Connects Quantum Similarity Testing to Atomtronics

  Researchers at the Indian Institute of Technology Patna have proposed a hybrid discrete-continuous quantum algorithm for comparing interferometric images. They apply it in numerical atomtronics simulations to identify interaction-driven nonlinearity that could support magnetic-field sensing.

• PsiQuantum Reports 1.2 dB Loss in AI Optical-Switch Demo

  PsiQuantum unveiled an 8×8 optical circuit switch built on its silicon photonics platform, reporting typical insertion loss of 1.2 dB in company lab tests. The company is sharing demonstration samples with selected prospective customers as it develops products for AI infrastructure.

• Delft Researchers Resolve Nuclear Spin Transitions in One Titanium Atom

  A Delft-led team used scanning tunnelling microscopy and electron–nuclear double resonance to resolve transitions in the nucleus of a single titanium-47 atom. Measurements across magnetic-field strengths revealed how hyperfine and quadrupole interactions shape the spectrum and showed the nucleus could be addressed when its coupling to the electron spin was weak.

• PSI Publishes Five AI-Assisted Quantum-Information Results

  Physical Superintelligence says its October 23, 2026, release presents five quantum-information results, each with a paper and Lean formalization. The results address Werner states, vacuum Bell correlations, CGLMP measurements, PPT maps and causal quantum processes.

• IDEMIA and KT Put Post-Quantum SIMs Into South Korea’s Defense Pilot

  IDEMIA Secure Transactions and KT are implementing NIST-standardized and Korean post-quantum algorithms on a SIM-equipped smart-card platform for South Korea’s 2026 pilot. The wider defense effort will assess post-quantum cryptography across PCs, surveillance systems, drones and 5G networks.

• PsiQuantum Demonstrates an 8×8 Optical Switch for AI Networks

  PsiQuantum announced an 8×8 optical circuit-switching demonstrator for AI data-center networks on October 28, 2026. The company reports 1.2 dB insertion loss, 40 dB crosstalk and reconfiguration in under 3 milliseconds in its lab tests.

• IonQ and EPB Report 95.8% Fewer Parameters in Grid AI Test

  IonQ and Chattanooga utility EPB report that a hybrid quantum-classical model used 95.8% fewer trainable parameters than a classical neural network in a 33-bus grid test. Separate studies tested quantum-assisted approaches to distribution network reconfiguration on benchmark networks and IonQ hardware.

• ZuriQ and Rhonexum Target Trapped-Ion Control Wiring

  ZuriQ and Rhonexum announced a multi-year commercial framework agreement covering cryogenic integrated-circuit technologies for ZuriQ to evaluate. An initial quantity of Rhonexum’s inaugural product is scheduled for delivery by the end of 2026.

• Antwerp Team Reads Carbon-Nanotube Spins at Room Temperature

  A University of Antwerp team reports room-temperature optical readout of triplet spin states in chemically modified carbon nanotubes. The researchers also detect a paramagnetic molecule, but low signal contrast and a noisy antenna demonstration remain obstacles to practical sensors.

• Quantum Broker Splits Circuit Shots Across Competing QPUs

  A paper posted October 20 introduces Quantum Broker, software that allocates a quantum circuit’s measurement shots among heterogeneous QPUs according to cost, timing and other service requirements. Tests on noisy simulators found a mean output-distribution score of 0.907 across 18 executions, but the authors say live-processor validation remains outstanding.

• NVision Tests Organic Qubits for Photonic Quantum Chips

  NVision reported a Nature study demonstrating optical control of a single organic molecule’s spin, a step toward molecular qubits for photonic chips. The Ulm-based company is partnering with HyperLight to develop its first chips.

• Pasqal Finds Three Relaxation Regimes in a 256-Qubit Quantum Magnet

  Pasqal reports three relaxation patterns in a 256-atom Rydberg simulation of a two-dimensional quantum magnet. The study finds a slow-relaxation regime where classical tensor-network calculations lose agreement at late times.

• OpenAI Says Its Models Proved QCD Exists

  OpenAI says its models produced a mathematical existence proof for quantum chromodynamics and related four-dimensional quantum field theories. The company is withholding the physics proof materials while an outside group led by David Gross examines the result.

• QunaSys Simulates a 319 Million-Gate Chemistry Circuit

  QunaSys says it simulated a 28-qubit, 319 million-gate quantum phase-estimation circuit for a four-hydrogen model using 1,024 NVIDIA H100 GPUs. The run took about 1.5 hours and produced an energy estimate within the stated chemical-accuracy threshold.

• Fixed-Basis Snapshots Recover Hidden Quantum Transport

  A numerical study shows how calibrated equilibrium relations can help researchers infer hidden conserved quantities from fixed-basis quantum measurements. The simulations recover energy and charge profiles and expose limits where symmetries or departures from local equilibrium can make readout ambiguous.

• Florida Switches On Its First Quantum-Safe Network Link

  Palm Beach State College and Florida Atlantic University activated a quantum key distribution link on October 15, the first operating segment of Florida’s planned statewide quantum-safe network. The $1 million FloridaCommerce-backed project uses Palm Beach County dark fiber, with additional South Florida connections planned.

• GKP Qubit Study Models Loss, Gates and Readout

  A PRX Quantum study models how loss, dephasing, logical gates and inefficient measurements affect superconducting Gottesman-Kitaev-Preskill qubits. Its proposed decoder changes cut modeled gate infidelity by about two orders of magnitude under ideal error correction, but by about one order when correction is approximate.