HRL Laboratories demonstrates an always-on exchange-only (AEON) silicon spin qubit at 99.86% average Clifford fidelity
An arXiv preprint (2508.01033, submitted 2025-08-01; subsequently published in Nature Communications) from HRL Laboratories (Joseph D. Broz, Jesse C. Hoke, Edwin Acuna, Jason R. Petta) reports the first demonstration of an always-on exchange-only (AEON) spin qubit operated with simultaneous exchange pulses in a triangular quantum-dot array, characterized by blind randomized benchmarking at an average single-qubit Clifford gate fidelity of 99.86%. Pulsing multiple non-commuting exchange interactions simultaneously reduces circuit depth and provides leakage protection relative to conventional exchange-only operation.
A credible experimental spin-qubit architecture demonstration from a commercial quantum-hardware lab, clearing section 7.3(a) on affiliation. The 99.86% Clifford fidelity is a named-metric result but not a record, and the AEON scheme's significance is architectural (circuit-depth and leakage reduction) rather than landscape-moving, placing it at the section 8 score-5 band — interesting within the silicon-spin sub-domain, not material outside it.
Simultaneous-exchange AEON control, if it extends to two-qubit operations and larger dot arrays, could ease the control-overhead and leakage problems that have held silicon spin qubits behind superconducting and ion-trap modalities on gate fidelity; HRL runs one of the more mature exchange-only programmes.