Work

Demonstration of an always-on exchange-only spin qubit

Year: 2026

Type: article

Abstract: In conventional exchange-only (EO) spin qubit demonstrations, quantum gates have been implemented using sequences of individually pulsed pairwise exchange interactions with only one exchange coupling active at a time. Alternatively, multiple non-commuting exchange interactions can be pulsed simultaneously, reducing circuit depths and providing protection against leakage. We demonstrate high-fidelity quantum control of an always-on exchange-only (AEON) qubit, operated using simultaneous exchange pulses in a triangular quantum dot (QD) array. We use blind randomized benchmarking to characterize the performance of the full AEON single-qubit Clifford gate set, achieving an average Clifford gate fidelity F C1 = 99.86%. Extensions of this work may enable more efficient EO two-qubit entangling gates as well as the implementation of native i -Toffoli gates in Loss-DiVincenzo single-spin qubits.

Source: Nature Communications

DOI: 10.1038/s41467-026-70943-w

Authors: Joseph D. Broz, Jesse C. Hoke, Edwin Acuna, Jason R. Petta

Institutions: HRL Laboratories (United States), University of California, Los Angeles

Language: English

Topic: Quantum and electron transport phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $6,990

Funder: Army Research Office