中国物理B ›› 2023, Vol. 32 ›› Issue (3): 30308-030308.doi: 10.1088/1674-1056/ac873b

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Electrical manipulation of a hole ‘spin’-orbit qubit in nanowire quantum dot: The nontrivial magnetic field effects

Rui Li(李睿) and Hang Zhang(张航)   

  1. Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
  • 收稿日期:2022-06-13 修回日期:2022-07-26 接受日期:2022-08-05 出版日期:2023-02-14 发布日期:2023-02-14
  • 通讯作者: Rui Li E-mail:ruili@ysu.edu.cn
  • 基金资助:
    This work was supported by the National Natural Science Foundation of China (Grant No. 11404020), the Project from the Department of Education of Hebei Province (Grant No. QN2019057), and the Starting up Foundation from Yanshan University (Grant No. BL18043).

Electrical manipulation of a hole ‘spin’-orbit qubit in nanowire quantum dot: The nontrivial magnetic field effects

Rui Li(李睿) and Hang Zhang(张航)   

  1. Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
  • Received:2022-06-13 Revised:2022-07-26 Accepted:2022-08-05 Online:2023-02-14 Published:2023-02-14
  • Contact: Rui Li E-mail:ruili@ysu.edu.cn
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (Grant No. 11404020), the Project from the Department of Education of Hebei Province (Grant No. QN2019057), and the Starting up Foundation from Yanshan University (Grant No. BL18043).

摘要: Strong ‘spin’-orbit coupled one-dimensional hole gas is achievable in a Ge nanowire in the presence of a strong magnetic field. The strong magnetic field lifts the two-fold degeneracy in the hole subband dispersions, so that the effective low-energy subband dispersion exhibits strong spin-orbit coupling. Here, we study the electrical spin manipulation in a Ge nanowire quantum dot for both the lowest and second lowest hole subband dispersions. Using a finite square well to model the quantum dot confining potential, we calculate exactly the level splitting of the spin-orbit qubit and the Rabi frequency in the electric-dipole spin resonance. The spin-orbit coupling modulated longitudinal g-factor gso is not only non-vanishing but also magnetic field dependent. Moreover, the spin-orbit couplings of the lowest and second lowest subband dispersions have opposite magnetic dependences, so that the results for these two subband dispersions are totally different. It should be noticed that we focus only on the properties of the hole ‘spin’ instead of the real hole spin.

关键词: quantum dot, hole spin, spin-orbit coupling, electric-dipole spin resonance

Abstract: Strong ‘spin’-orbit coupled one-dimensional hole gas is achievable in a Ge nanowire in the presence of a strong magnetic field. The strong magnetic field lifts the two-fold degeneracy in the hole subband dispersions, so that the effective low-energy subband dispersion exhibits strong spin-orbit coupling. Here, we study the electrical spin manipulation in a Ge nanowire quantum dot for both the lowest and second lowest hole subband dispersions. Using a finite square well to model the quantum dot confining potential, we calculate exactly the level splitting of the spin-orbit qubit and the Rabi frequency in the electric-dipole spin resonance. The spin-orbit coupling modulated longitudinal g-factor gso is not only non-vanishing but also magnetic field dependent. Moreover, the spin-orbit couplings of the lowest and second lowest subband dispersions have opposite magnetic dependences, so that the results for these two subband dispersions are totally different. It should be noticed that we focus only on the properties of the hole ‘spin’ instead of the real hole spin.

Key words: quantum dot, hole spin, spin-orbit coupling, electric-dipole spin resonance

中图分类号:  (Quantum computation architectures and implementations)

  • 03.67.Lx
73.21.La (Quantum dots) 71.70.Ej (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect) 76.30.-v (Electron paramagnetic resonance and relaxation)