Abstract
Magnetic measurements under high-pressure conditions are pivotal for the study of superconductivity and magnetic materials but remain challenging due to the micrometer-sized sample in diamond anvil cells (DAC). In this study, we propose a quantum sensing approach utilizing negatively charged boron-vacancy (V_B⁻) spin defects in two-dimensional hexagonal boron nitride for high resolution magnetic measurements under pressure. The optical and spin properties of VB⁻ defects were systematically studied under high-pressure conditions, revealing a significant pressure-induced shift in zero-field splitting (ZFS), approximately three times larger than that of nitrogen-vacancy (NV) center. Furthermore, we demonstrate the pressure-dependent magnetic transition and variations in the Curie temperature of van der Waals ferromagnet Fe₃GeTe₂ flake using V_B⁻ defects under pressures. Notably, the maximum operational pressure for V_B⁻ defects was determined to be approximately 11 GPa, attributed to a structural phase transition in hexagonal boron nitride (hBN). This work establishes the way for two-dimensional quantum sensing technologies under high-pressure environments.