The Daily · Thursday 22 October 2026

The day in brief

Oxford researchers transferred remote entanglement from strontium ions to calcium memory qubits, which retained 69(4)% fidelity after 10 seconds ².

Fraunhofer IAF demonstrated 100% optical contrast with a diamond-based laser-threshold magnetometer ³. The prototype reported photon-shot-noise-limited sensitivity below 400 fT/√Hz in a vector configuration ³. Alice & Bob operated three cat-qubit demonstrators, but its measured logical error rate has not yet fallen below threshold ⁴.

Changhao Yi and Cunlu Zhou described a parity-based protocol for estimating many-body Green’s functions without ancilla qubits or controlled time evolution in the measurement circuit ⁵. Northwestern researchers trapped a single positron and resolved its cyclotron and spin states, but have not yet measured its magnetic moment ⁶. Qblox reported round-trip latency below 4.0 microseconds with an NVIDIA RTX PRO 6000 Blackwell GPU ¹⁰.

The four

• Oxford Stores Remote Ion Entanglement in Calcium for 10 Seconds

  An Oxford quantum-network experiment transferred entanglement between remote strontium ions to calcium memory qubits and stored it for about 10 seconds. The study also created mixed-species entangled states involving as many as four matter qubits.

  Source · Physical Review Letters

• 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.

  Source · Fraunhofer Institute for Applied Solid State Physics IAF

• Alice & Bob Tests Three Cat-Qubit Demonstrators for PROQCIMA

  Alice & Bob reports operating three cat-qubit demonstrators for Phase 1 of France’s PROQCIMA programme. The tests covered error-correction operations, but the measured logical error rate has not yet fallen below threshold.

  Source · Alice & Bob

• Yi and Zhou Use Parity to Simplify Green’s-Function Measurements

  Changhao Yi and Cunlu Zhou describe a parity-based protocol for estimating many-body Green’s functions without ancilla qubits or controlled time evolution in the measurement circuit. Numerical simulations test the method on Fermi–Hubbard and XXZ models, while the paper identifies hardware demonstrations and improved noise guarantees as next steps.

  Source · Quantum

Also today

• Northwestern Team Traps One Positron in a Quantum Cyclotron
• Columbia Team Finds Trapped Electron Waves in a 2D Metal
• QMatter Team Runs 52-Qubit Chemistry in a Million-Atom Protein Model
• IBM and Rutgers Steer Quantum Chaos Across 100 Qubits
• Qblox Reports Sub-4-Microsecond GPU–Quantum-Control Latency
• Qiskit 2.6 Brings Custom Compiler Passes to Its C API
• UCF Wins $400,000 DOE Grant for Partially Fault-Tolerant Tools
• Quantum X Reports 12.7% Fewer Errors on Google Data
• Optical Experiment Recovers 10.3% of Lost State Purity
• Toshiba Launches Hub-Based Quantum-Safe Networking Platform
• RhymeQ Raises $2.2 Million to Bring Python Developers to Quantum
• IBM Gate Patterns Bias Neighboring Qubits in New Tests
• Franco-Rubio, Bochniak and Cirac Map Defects in Matrix-Product States
• Hartree Theory Fails for Some Non-Hermitian Boson Dynamics
• Alice & Bob Team Maps a Dissipative Phase Diagram with 7x Fewer Solves
• Szalay Adds a W-Entanglement Measure for Three Qubits
• NPL Gets £230,000 to Scale Ion-Trap Packaging
• qBraid Launches OS for Quantum Hardware Operators
• Bechtle Adds IQM Quantum Systems to DLR Initiative
• South Korea Expands Quantum Testbeds Into Three Hubs

The paper of the day

• ArcTN: Efficient Tensor-Network Contraction Planning for Quantum Circuit Simulation

The event of the day

• Q+AI 2026 (3.0): Quantum + AI

Every issue

1. Sunday 1 November 2026 — Luthra and Owens Demonstrate QLDPC Surgery on Quantinuum H2-2
2. Saturday 31 October 2026 — IDEMIA Wins First EMVCo Certification for PQC Payment Cards
3. Friday 30 October 2026 — One Transmon Connects Two Superconducting Waveguides
4. Thursday 29 October 2026 — Researchers Demonstrate a Single-Molecule Spin–Photon Interface
5. Wednesday 28 October 2026 — USTC Researchers Demonstrate Four-Way Multiplexed Quantum Gates
6. Tuesday 27 October 2026 — IBM Team Entangles Logical Qubits on Nighthawk Processor
7. Monday 26 October 2026 — Intel Agrees to Acquire Classiq for Full-Stack Quantum Computing
8. Sunday 25 October 2026 — Treasury Proposes Wider Controls on Quantum Investment
9. Saturday 24 October 2026 — Treasury Proposes Wider Controls on Quantum Investment
10. Friday 23 October 2026 — Single-Ion Error Correction Extends Qubit Lifetime 12.9-Fold
11. Thursday 22 October 2026 — Oxford Stores Remote Ion Entanglement in Calcium for 10 Seconds