Fast and High-Fidelity State Preparation and Measurement in Triple-Quantum-Dot Spin Qubits
2022; American Physical Society; Volume: 3; Issue: 1 Linguagem: Inglês
10.1103/prxquantum.3.010352
ISSN2691-3399
AutoresJacob Blumoff, Andrew Pan, Tyler Keating, Reed W. Andrews, David W. Barnes, T. Brecht, E. T. Croke, Larken E. Euliss, Jacob A. Fast, Clayton Jackson, Aaron M. Jones, Joseph Kerckhoff, Robert Lanza, Kate Raach, Bryan J. Thomas, Roland Velunta, Aaron Weinstein, Thaddeus D. Ladd, Kevin Eng, Matthew Borselli, A. T. Hunter, Matthew T. Rakher,
Tópico(s)Semiconductor materials and devices
ResumoWe demonstrate rapid high-fidelity state preparation and measurement in exchange-only Si/SiGe triple-quantum-dot qubits. Fast measurement integration (980-ns) and initialization (approximately 300-ns) operations are performed with all-electrical baseband control. We emphasize a leakage-sensitive joint initialization and measurement metric, developed in the context of exchange-only qubits but applicable more broadly, and report an infidelity of 2.5±0.5×10−3. This result is enabled by a high-valley-splitting heterostructure, initialization at the two- to three-electron charge boundary, and careful assessment and mitigation of T1 during spin-to-charge conversion. The ultimate fidelity is limited by a number of comparably important factors and we identify clear paths toward further improved fidelity and speed. Along with an observed single-qubit randomized benchmarking error rate of 1.7×10−3, this work demonstrates initialization, control, and measurement of Si/SiGe triple-dot qubits at fidelities and durations that are promising for scalable quantum information processing.3 MoreReceived 21 December 2021Revised 23 February 2022Accepted 9 March 2022DOI:https://doi.org/10.1103/PRXQuantum.3.010352Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum computationQuantum information with solid state qubitsQuantum Information
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