Negatively charged silicon vacancy (SiV) center in diamonds are leading candidates for solid-state quantum memories that can be controlled using electromagnetic or acoustic waves. The latter are particularly promising due to strong strain response of SiV, enabling large spin-phonon interaction strengths. Indeed, coherent spin control via surface acoustic waves (SAW) has been demonstrated and is essential for developing on-chip phononic quantum networks. However, the absence of piezoelectricity in diamond requires interfacing with a piezoelectric material for efficient transduction and delivery of acoustic waves to spins in diamonds. Here, we demonstrate a heterogeneously integrated phononic platform that combines thin-film lithium niobate (TFLN) with diamond to enable acoustic control of single SiV spins. Additionally, leveraging large SAW-induced strain at the location of SiV, we achieve coherent acoustic control of an electron spin with more than twofold improvement in Rabi frequency compared to the state-of-the-art devices based on aluminum nitride-on-diamond. This work represents a crucial step towards realizing phonon-based quantum information processing systems.
@article{arxiv.2505.08895,
title = {Thin Film Lithium Niobate on Diamond (LiNDa) platform for Efficient Spin-Phonon Coupling},
author = {Zhujing Xu and Sophie Weiyi Ding and Eliza Cornell and Salma Mohideen and Matthew Yeh and Kazuhiro Kuruma and Leticia Magalhaes and Amirhassan Shams-Ansari and Benjamin Pingault and Marko Loncar},
journal= {arXiv preprint arXiv:2505.08895},
year = {2025}
}