Electrically Tuneable Variability in Germanium Hole Spin Qubits

• URL: http://arxiv.org/abs/2512.12702v1
• Date: Sun, 14 Dec 2025 14:12:31 GMT
• Title: Electrically Tuneable Variability in Germanium Hole Spin Qubits
• Authors: Edmondo Valvo, Michele Jakob, Patrick Del Vecchio, Maximilian Rimbach-Russ, Stefano Bosco,
• Abstract summary: Hole spin qubits in planar germanium heterostructures are frontrunners for scalable semiconductor quantum computing.<n>We propose a systematic and local method to engineer the spin qubit response by imprinting a controlled anisotropy in the quantum dot confinement.<n>Our results provide practical design principles for on-demand control of the spin response and mitigating variability, paving the way towards large-scale germanium-based quantum computers.
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• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Hole spin qubits in planar germanium heterostructures are frontrunners for scalable semiconductor quantum computing. However, their current performance is mostly limited by large dot-to-dot variability that leads to uncontrolled qubit energies and random tilts in the spin quantization axis. Here, we propose a systematic and local method to engineer the spin qubit response by imprinting a controlled anisotropy in the quantum dot confinement, enabling on-demand electric g-tensor control. In particular, we find that both the quantum-dot size and asymmetry allow electrical tuning of the g-tensor and significantly suppress magnitude and angular variability of the spin response for selected magnetic field directions. We confirm this behavior by analyzing single-disorder realizations and statistical ensembles in state-of-the-art strained and unstrained germanium channels, showing that the latter provides an optimal path for $g$-tensor engineering. Our results provide practical design principles for on-demand control of the spin response and mitigating variability, paving the way towards large-scale germanium-based quantum computers.

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