Journal Article

Benchmarking Gate Fidelities in a Si / SiGe Two-Qubit Device

Wehner, S., Coppersmith, S. N., Watson, T. F., Eriksson, M. A., Helsen, J., Savage, D. E., Xue, X., Ward, D. R., Lagally, M. G., Vandersypen, L. M. K.

2019

Overview

We report the first complete characterization of single-qubit and two-qubit gate fidelities in silicon-based spin qubits, including cross talk and error correlations between the two qubits. To do so, we use a combination of standard randomized benchmarking and a recently introduced method called character randomized benchmarking, which allows for more reliable estimates of the two-qubit fidelity in this system, here giving a 92% fidelity estimate for the controlled-Zgate. Interestingly, with character randomized benchmarking, the two-qubit gate fidelity can be obtained by studying the additional decay induced by interleaving the two-qubit gate in a reference sequence of single-qubit gates only. This work sets the stage for further improvements in all the relevant gate fidelities in silicon spin qubits beyond the error threshold for fault-tolerant quantum computation.

• Publisher: American Physical Society
• Subject: Accuracy / Benchmarks / CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS / Condensed Matter & Materials Physics / Crosstalk / Decay / Double quantum dots / Electron spin resonance / Fault tolerance / Gates / Physical Systems / Physics / PHYSICS OF ELEMENTARY PARTICLES AND FIELDS / Quantum benchmarking / Quantum computing / Quantum gates / Quantum Information / Quantum information with solid state qubits / Qubits (quantum computing) / Silicon