Rapid Single-Shot Measurement of a Singlet-Triplet Qubit

C Barthel,A C Gossard,D J Reilly,M P Hanson,C M Marcus

doi:10.1103/physrevlett.103.160503

C Barthel, A C Gossard + Show 3 more

Open Access

https://doi.org/10.1103/physrevlett.103.160503

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Abstract

We report repeated single-shot measurements of the two-electron spin state in a GaAs double quantum dot. The readout allows measurement with a fidelity above 90% with a approximately 7 micros cycle time. Hyperfine-induced precession between singlet and triplet states of the two-electron system are directly observed, as nuclear Overhauser fields are quasistatic on the time scale of the measurement cycle. Repeated measurements on millisecond to second time scales reveal the evolution of the nuclear environment.

Highlights

We report repeated single-shot measurements of the two-electron spin state in a GaAs double quantum dot
Hyperfine-induced precession between singlet and triplet states of the two-electron system are directly observed, as nuclear Overhauser fields are quasi-static on the time scale of the measurement cycle
Single-shot measurements of solidstate quantum systems have been reported for superconducting qubits [10], the charge state of a single quantum dot [11], the spin of a single electron in a quantum dot in large magnetic fields [12, 13], and the two-electron spin state in a single quantum dot [14]

Summary

Introduction

Rapid single-shot measurement of a singlet-triplet qubit. We report repeated single-shot measurements of the two-electron spin state in a GaAs double quantum dot.

Results

Conclusion