Correlations of spin splitting and orbital fluctuations due to 1/f charge noise in the Si/SiGe Quantum Dot

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Main Authors: Kępa, Marcin, Cywiński, Łukasz, Krzywda, Jan A.
Format: Preprint
Published: 2023
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author Kępa, Marcin
Cywiński, Łukasz
Krzywda, Jan A.
author_facet Kępa, Marcin
Cywiński, Łukasz
Krzywda, Jan A.
contents Fluctuations of electric fields can change the position of a gate-defined quantum dot in a semiconductor heterostructure. In the presence of magnetic field gradient, these stochastic shifts of electron's wavefunction lead to fluctuations of electron's spin splitting. The resulting spin dephasing due to charge noise limits the coherence times of spin qubits in isotopically purified Si/SiGe quantum dots. We investigate the spin splitting noise caused by such process caused by microscopic motion of charges at the semiconductor-oxide interface. We compare effects of isotropic and planar displacement of the charges, and estimate their densities and typical displacement magnitudes that can reproduce experimentally observed spin splitting noise spectra. We predict that for defect density of $10^{10}$ cm$^{-2}$, visible correlations between noises in spin splitting and in energy of electron's ground state in the quantum dot, are expected.
format Preprint
id arxiv_https___arxiv_org_abs_2305_06011
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Correlations of spin splitting and orbital fluctuations due to 1/f charge noise in the Si/SiGe Quantum Dot
Kępa, Marcin
Cywiński, Łukasz
Krzywda, Jan A.
Mesoscale and Nanoscale Physics
Fluctuations of electric fields can change the position of a gate-defined quantum dot in a semiconductor heterostructure. In the presence of magnetic field gradient, these stochastic shifts of electron's wavefunction lead to fluctuations of electron's spin splitting. The resulting spin dephasing due to charge noise limits the coherence times of spin qubits in isotopically purified Si/SiGe quantum dots. We investigate the spin splitting noise caused by such process caused by microscopic motion of charges at the semiconductor-oxide interface. We compare effects of isotropic and planar displacement of the charges, and estimate their densities and typical displacement magnitudes that can reproduce experimentally observed spin splitting noise spectra. We predict that for defect density of $10^{10}$ cm$^{-2}$, visible correlations between noises in spin splitting and in energy of electron's ground state in the quantum dot, are expected.
title Correlations of spin splitting and orbital fluctuations due to 1/f charge noise in the Si/SiGe Quantum Dot
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2305.06011