Feedback control of qubits is a highly demanded technique for advanced quantum information protocols such as quantum error correction. Here we demonstrate active reset of a silicon spin qubit using feedback control. The active reset is based on quantum non-demolition readout of the qubit and feedback according to the readout results, which is enabled by hardware data processing and sequencing. We incorporate a cumulative readout technique to the active reset protocol, enhancing initialization fidelity above a limitation imposed by accuracy of the single QND measurement fidelity. Based on an analysis of the reset protocol, we suggest a way to achieve the initialization fidelity sufficient for the fault-tolerant quantum computation.
@article{arxiv.2209.02259,
title = {Feedback-based active reset of a spin qubit in silicon},
author = {Takashi Kobayashi and Takashi Nakajima and Kenta Takeda and Akito Noiri and Jun Yoneda and Seigo Tarucha},
journal= {arXiv preprint arXiv:2209.02259},
year = {2023}
}