Surface Acoustic Wave Cavity Optomechanics with Atomically Thin h-BN and WSe2 Single-Photon Emitters

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 twodimensional (2D) materials, specifically monolayer WSe2 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 35 meV/% for WSe2 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 WSe2 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.