主讲人：黄培豪 助理研究员（南方科技大学）

题目：Electrical control of spin qubits in semiconductor quantum dots

时间：2022年12月19日上午11:00

会议ID：（腾讯会议）825-745-004

联系人：吴威

报告摘要：

Spin qubits in semiconductor quantum dots hold promise for quantum information processing due to its scalability and long coherence. Recently, significant progress has been made for the manipulation of electron-spin and hole-spin qubits in gate-defined quantum dots and single-atom dopants. Here, we present our recent studies on the electrical control of spin-valley qubits in silicon quantum dots and hole-spin qubits in single-atom acceptor. In gate-defined silicon quantum dots, we show that it is possible to significantly enhance the electrical manipulation of a spin qubit through interference and spin-valley mixing [1]. In the presence of spin-valley mixing, there are two sweet spots for spin manipulation, where the quality factor of the spin qubit is improved. We further reveal that the synthetic spin-orbit coupling (SOC) leads to distinctive spin relaxation in silicon, which provides a theoretical understanding of the recent experimental results. In a single boron dopant, we study the electrical manipulation of a hole-spin. Hole spin qubit is widely studied recently. However, hole-spin in acceptors is less discussed compared to that in quantum dot. We show that, in the presence of strain two sweet-spots appear, where decoherence from electrical noise is suppressed. The strain also induces electrical manipulation of spin qubit. Moreover, the tunable strain reduces the required strength of electric field for the "sweet spot", and optimizes the manipulation performance of the spin qubit in boron [2]. In addition, we discusses the implementation of high fidelity two-qubit gate based on electric dipole-dipole coupling. The results could have potential applications in spin-based quantum computing.

[1] NPJ Quantum Inf. 7, 162 (2021).

[2] arXiv:2211.10019.

个人简介：

Peihao Huang got his Ph.D. from Shanghai Jiao Tong University. He has held Postdoc positions at the University at Buffalo, and National Institutes and Standards and Technologies; and Joined the Southern University of Science and Technology (SUSTech) in 2018. Peihao's current research interest is on the theoretical aspects of solid-state quantum computing and quantum simulation. He has published scientific papers in renowned journals, such as NPJ Quantum Inf., Nano Lett., Adv. Quantum Technol., Phys. Rev. B/A/Appl., and New J Phys..