Electrical operation of hole spin qubits in planar MOS silicon quantum dots

Fuente: arXiv
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Main Authors: Wang, Zhanning, Sarkar, Abhikbrata, Liles, S. D., Saraiva, Andre, Dzurak, A. S., Hamilton, A. R., Culcer, Dimitrie
Format: Preprint
Published: 2023
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author Wang, Zhanning
Sarkar, Abhikbrata
Liles, S. D.
Saraiva, Andre
Dzurak, A. S.
Hamilton, A. R.
Culcer, Dimitrie
author_facet Wang, Zhanning
Sarkar, Abhikbrata
Liles, S. D.
Saraiva, Andre
Dzurak, A. S.
Hamilton, A. R.
Culcer, Dimitrie
contents Silicon hole quantum dots have been the subject of considerable attention thanks to their strong spin-orbit coupling enabling electrical control. The physics of silicon holes is qualitatively different from germanium holes and requires a separate theoretical description. In this work, we theoretically study the electrical control and coherence properties of silicon hole dots with different magnetic field orientations. We discuss possible experimental configurations to optimize the electric dipole spin resonance (EDSR) Rabi time, the phonon relaxation time, and the dephasing due to random telegraph noise. Our main findings are: (i) The in-plane $g$-factor is strongly influenced by the presence of the split-off band, as well as by any shear strain. The $g$-factor is a non-monotonic function of the top gate electric field, in agreement with recent experiments. This enables coherence sweet spots at specific values of the top gate field and specific magnetic field orientations. (ii) Even a small ellipticity (aspect ratios $\sim 1.2$) causes significant anisotropy in the in-plane $g$-factor, which can vary by $50\% - 100\%$ as the magnetic field is rotated in the plane. (iii) EDSR Rabi frequencies are comparable to Ge, and the ratio between the relaxation time and the EDSR Rabi time $\sim 10^5$. For an out-of-plane magnetic field the EDSR Rabi frequency is anisotropic with respect to the orientation of the driving electric field, varying by $\approx 20\%$ as the driving field is rotated in the plane. Our work aims to stimulate experiments by providing guidelines on optimizing configurations and geometries to achieve robust, fast and long-lived hole spin qubits in silicon.
format Preprint
id arxiv_https___arxiv_org_abs_2309_12243
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Electrical operation of hole spin qubits in planar MOS silicon quantum dots
Wang, Zhanning
Sarkar, Abhikbrata
Liles, S. D.
Saraiva, Andre
Dzurak, A. S.
Hamilton, A. R.
Culcer, Dimitrie
Mesoscale and Nanoscale Physics
Silicon hole quantum dots have been the subject of considerable attention thanks to their strong spin-orbit coupling enabling electrical control. The physics of silicon holes is qualitatively different from germanium holes and requires a separate theoretical description. In this work, we theoretically study the electrical control and coherence properties of silicon hole dots with different magnetic field orientations. We discuss possible experimental configurations to optimize the electric dipole spin resonance (EDSR) Rabi time, the phonon relaxation time, and the dephasing due to random telegraph noise. Our main findings are: (i) The in-plane $g$-factor is strongly influenced by the presence of the split-off band, as well as by any shear strain. The $g$-factor is a non-monotonic function of the top gate electric field, in agreement with recent experiments. This enables coherence sweet spots at specific values of the top gate field and specific magnetic field orientations. (ii) Even a small ellipticity (aspect ratios $\sim 1.2$) causes significant anisotropy in the in-plane $g$-factor, which can vary by $50\% - 100\%$ as the magnetic field is rotated in the plane. (iii) EDSR Rabi frequencies are comparable to Ge, and the ratio between the relaxation time and the EDSR Rabi time $\sim 10^5$. For an out-of-plane magnetic field the EDSR Rabi frequency is anisotropic with respect to the orientation of the driving electric field, varying by $\approx 20\%$ as the driving field is rotated in the plane. Our work aims to stimulate experiments by providing guidelines on optimizing configurations and geometries to achieve robust, fast and long-lived hole spin qubits in silicon.
title Electrical operation of hole spin qubits in planar MOS silicon quantum dots
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2309.12243