PRX Quantum (Feb 2024)
Surface Acoustic Wave Cavity Optomechanics with Atomically Thin h-BN and WSe_{2} Single-Photon Emitters
Abstract
Surface acoustic waves (SAWs) are a versatile tool for coherently interfacing with a variety of solid-state quantum systems spanning microwave to optical frequencies, including superconducting qubits, spins, and quantum emitters. Here, we demonstrate SAW cavity optomechanics with quantum emitters in two-dimensional (2D) materials, specifically monolayer WSe_{2} and h-BN, on a planar lithium niobate SAW resonator driven by superconducting electronics. Using steady-state photoluminescence spectroscopy and time-resolved single-photon counting, we map the temporal dynamics of modulated 2D emitters under coupling to different SAW cavity modes, showing energy-level splitting consistent with deformation potential coupling of 35meV/% for WSe_{2} and 12.5 meV/% for h-BN visible-light emitters. We leverage the large anisotropic strain from the SAW to modulate the excitonic fine-structure splitting in WSe_{2} on a nanosecond timescale, which may find applications for on-demand entangled-photon-pair generation from 2D materials. Cavity optomechanics with SAWs and 2D quantum emitters provide opportunities for compact sensors and quantum electro-optomechanics in a multifunctional integrated platform that combines phononic, optical, and superconducting electronic quantum systems.