Acoustically modulated optical emission of hexagonal boron nitride layers

TL;DR

This study demonstrates how surface acoustic waves can dynamically modulate the optical emission of defect centers in hexagonal boron nitride layers, enabling control over their electronic states.

Contribution

It provides the first systematic analysis of acoustic wave effects on defect emission in 2D materials, including quantification of deformation potential and stabilization mechanisms.

Findings

Emission intensity varies by up to 50% with acoustic modulation

Emission energy oscillates with an amplitude of nearly 1 meV

Hydrostatic deformation potential estimated at 40 meV/%

Abstract

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 LiNbO$_3$ substrate. The dynamic strain field of the surface acoustic waves modulates the emission lines resulting in intensity variations as large as 50% and oscillations of the emission energy with an amplitude of almost 1 meV. 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 material of about 40 meV/%. Furthermore, we show that the dynamic piezoelectric field of the acoustic wave could 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 two-dimensional materials.