Surface acoustic wave-induced strain engineering for quantum dot control in a non-piezoelectric material

In this paper, we explore alternative approaches to integrate acoustic wave functionalities into non-piezoelectric group IV materials, notably, germanium within germanium-on-silicon (GoS) heterostructures. This material system is promising as a spin qubit platform for scalable quantum computing architectures. We investigate the potential of surface acoustic waves (SAWs) inducing strain as an interaction mechanism that can be used for the manipulation of spin quantum states in lateral gated quantum dot (QD) devices. Using the Bir–Pikus formalism and k · p theory, we describe the theoretical basis for strain-induced modulation of the valence band in the GoS heterostructures. Our simulations demonstrate that the Rayleigh-type SAWs operating at GHz frequencies can create strain profiles that effectively modulate energy levels in quantum dots. Furthermore, replacing the piezoelectric material (AlN in this work) with a non-piezoelectric counterpart (Al2O3) preserves high-quality acoustic wave propagation while enabling purely mechanical coupling mechanisms, thus enhancing qubit coherence by reducing charge noise, which in piezoelectric materials stems from direct coupling between charge fluctuations and phonons. Proxy simulations with a double-plunger-gate system and floating potentials confirm the sensitivity of QD charge configuration energies to induced strain. These findings support SAW-driven detuning and align with recent predictions on strain-mediated spin–orbit coupling in hole spin qubits. This study highlights the promise of SAW-based strain engineering for scalable quantum control in CMOS-compatible platforms, paving the way for future experimental validation and integration with phononic crystals to advance mechanically enabled quantum architectures.