Surface Acoustic Wave Cavity Optomechanics with WSe$_2$ Single Photon Emitters

TL;DR

This paper demonstrates the coupling of surface acoustic wave (SAW) cavities with quantum emitters in monolayer WSe$_2$, enabling dynamic control of excitonic states and potential applications in quantum photonics and sensing.

Contribution

It introduces the first integration of SAW cavity optomechanics with 2D quantum emitters, showing energy-level splitting and strain modulation of excitons in WSe$_2$.

Findings

Energy-level splitting consistent with deformation potential coupling.

Nanosecond modulation of excitonic fine-structure splitting.

Potential for on-demand entangled photon-pair generation.

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 2D materials, specifically monolayer WSe$_2$, 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 30 meV/%. We leverage the large anisotropic strain from the SAW to modulate the excitonic fine-structure splitting 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 provides opportunities for compact sensors and quantum electro-optomechanics in a multi-functional integrated platform that combines phononic, optical, and superconducting electronic quantum systems.