Acoustically modulated optical emission of hexagonal boron nitride layers.

We investigate the effect of surface acoustic waves on the atomic-like optical emission from defect centers in hexagonal boron nitride layers deposited on the surface of a LiNbO3 substrate. The dynamic strain field of the surface acoustic waves modulates the emission lines resulting in intensity variations as large as 50%. From a systematic study of the dependence of the modulation on the acoustic wave power, we determine a hydrostatic deformation potential for defect centers in this two-dimensional (2D) material of about 40 meV/%. Furthermore, we show that the dynamic strain and piezoelectric fields of the acoustic wave contribute to the stabilization of the optical properties of these centers. Our results show that surface acoustic waves are a powerful tool to modulate and control the electronic states of 2D materials.