Ultrasensitive Pressure Sensing with Boron Vacancy Defects in Hexagonal Boron Nitride: <i>In-Situ</i> Pressure Imaging of Two-Dimensional Heterostructures under High Pressure
Cheng Zhong, Di Mai, Yupeng Wang, He Wang, Rucheng Dai, Zhongping Wang, Xiaoyu Sun, Zengming Zhang
Abstract
In-situ pressure imaging poses significant challenges due to strict experimental conditions. In this work, we integrate two-dimensional (2D) hexagonal boron nitride ( h BN) with negative boron vacancy (V B – ) spin defects directly into the chamber of the diamond anvil cell (DAC), enabling the first systematic investigation of their optical and spin properties under high pressure. Pressure-induced red-shifts of photoluminescence and reduced photon counts of the V B – defects are observed. The zero-field splitting parameter D of the V B – defects exhibits a linear pressure dependency at 57.4 MHz/GPa, with a pressure sensitivity of 0.32 MPa / Hz, surpassing that of the nitrogen-vacancy centers in diamond and the silicon-vacancy centers in silicon carbon. Furthermore, by utilizing the V B – defects as ultrasensitive pressure quantum sensors, we have successfully mapped the inhomogeneous pressure distribution within an h BN/twisted double trilayer graphene/ h BN device under compression via wide-field quantum imaging. The images reveal a pressure gradient increasing with loading. These results provide insight into the spin properties of V B – defects and the potential of in-situ pressure and magnetic imaging for 2D heterojunction devices under extreme conditions.