Spin Qubit Driving in Germanium via Elliptical g-Tensor Modulation by Surface Acoustic Waves

Chun-Yang Yuan^1*, Tzu-Kan Hsiao¹

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Chun-Yang Yuan, email:happy98901@gmail.com

Germanium-based spin qubits are a promising platform for scalable quantum computing. A key challenge is to perform quantum operations efficiently, for instance, during qubit shuttling. Here, we numerically investigate a spin driving mechanism using surface acoustic waves (SAWs) on a Ge quantum well platform, which leverages g-tensor modulation resonance. Our simulations reveal a striking asymmetry in the Rabi frequency as the in-plane magnetic field angle is varied. We attribute this phenomenon to a phase difference between the SAW-induced strain components, which leads to an elliptical, rather than linear, modulation of the hole g-tensor. This discovery of an inherent elliptical driving mechanism is crucial for designing high-fidelity quantum gates and optimizing qubit control in Ge-based architectures.

Keywords: Spin Qubit, Germanium, Surface Acoustic Wave, g-Tensor Modulation