Gate Control of g-factor in Germanium Quantum Dots: A Strain-Based Explanation

Abstract

The g-factor is a key parameter governing the behavior of semiconductor spin qubits, as it directly determines the qubit frequency and its sensitivity to electrical and magnetic noise. Recent experiments in germanium quantum dots have revealed large g-factor variations under small gate voltage changes, indicating a strong coupling between electrostatics and spin properties. Here, we present a quantitative explanation based on strain-induced g-tensor modulation. By combining finite-element simulations of inhomogeneous strain with quantum calculations of hole wavefunctions, we show that device-induced strain produces spatially varying g-tensors. Gate voltages shift the quantum dot within this landscape, leading to substantial changes in the effective g-factor. Our results may account for the experimentally observed tunability and highlight the importance of in-plane g-tensor variations. This work establishes a direct link between strain, electrostatic control, and qubit performance in germanium spin qubits.

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BibTeX RIS

BibTeX

@misc{niu2026gate,
  title = {{Gate Control of g-factor in Germanium Quantum Dots: A Strain-Based Explanation}},
  author = {Mu Niu and Adrian Culver and Johnathan Bryan and Chris Anderson and Mark Gyure and HongWen Jiang},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2608.12718},
  eprint = {2608.12718},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2608.12718},
  note = {CC BY 4.0},
}

RIS

TY  - UNPB
TI  - Gate Control of g-factor in Germanium Quantum Dots: A Strain-Based Explanation
AU  - Mu Niu
AU  - Adrian Culver
AU  - Johnathan Bryan
AU  - Chris Anderson
AU  - Mark Gyure
AU  - HongWen Jiang
PY  - 2026
DA  - 2026/09/11
PB  - arXiv
DO  - 10.48550/arxiv.2608.12718
UR  - https://arxiv.org/abs/2608.12718
AB  - The g-factor is a key parameter governing the behavior of semiconductor spin qubits, as it directly determines the qubit frequency and its sensitivity to electrical and magnetic noise. Recent experiments in germanium quantum dots have revealed large g-factor variations under small gate voltage changes, indicating a strong coupling between electrostatics and spin properties. Here, we present a quantitative explanation based on strain-induced g-tensor modulation. By combining finite-element simulations of inhomogeneous strain with quantum calculations of hole wavefunctions, we show that device-induced strain produces spatially varying g-tensors. Gate voltages shift the quantum dot within this landscape, leading to substantial changes in the effective g-factor. Our results may account for the experimentally observed tunability and highlight the importance of in-plane g-tensor variations. This work establishes a direct link between strain, electrostatic control, and qubit performance in germanium spin qubits.
ER  -

Abstract

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