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arXiv · 2602.21287

Anisotropy reduction and tunability of hole-spin qubit g-factor in strained parabolic Ge/SiGe quantum wells

R. K. L. Colmenar·Arthur Lin·Omadillo Abdurazakov·Yun-Pil Shim·Garnett W. Bryant·Charles Tahan
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Abstract

Hole-spin qubits in planar Ge/SiGe heterostructures have attracted significant attention in recent years owing to their favorable electrical characteristics and prolonged coherence times. However, the strong spin-orbit interaction also makes them susceptible to charge noise and inhomogeneous strain. This is further exacerbated by the highly anisotropic g-factor of the planar design. Although there are some known strategies to suppress charge noise, one approach is to engineer an isotropic g-factor. In this work we analyze how qubit confinement profile affects the g-factor of hole-spin qubits. We show that decreasing the characteristic in-plane qubit confinement length reduces the g-factor anisotropy. We perform analytical and numerical analysis to compare two types of quantum wells: square wells and parabolic wells. We show that square wells have limited tunability, while parabolic wells offer broader tunability, making them more promising for qubit engineering.

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R. K. L. Colmenar, Arthur Lin, Omadillo Abdurazakov, Yun-Pil Shim, Garnett W. Bryant, Charles Tahan. 2026-02-24. Anisotropy reduction and tunability of hole-spin qubit g-factor in strained parabolic Ge/SiGe quantum wells. https://arxiv.org/abs/2602.21287

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