posted on 2023-06-26, 20:04authored byFeifei Zhou, Zhengzhi Jiang, Haidong Liang, Shihao Ru, Andrew A. Bettiol, Weibo Gao
Spin defects existing in van der Waals materials attract
wide attention
thanks to their natural advantages for in situ quantum
sensing, especially the negatively charged boron vacancy (VB–) centers
in hexagonal boron nitride (h-BN). Here we systematically
investigate the laser and microwave power broadening in continuous-wave
optically detected magnetic resonance (ODMR) of the VB– ensemble
in h-BN, by revealing the behaviors of ODMR contrast
and line width as a function of the laser and microwave powers. The
experimental results are well explained by employing a two-level simplified
model of ODMR dynamics. Furthermore, with optimized power, the DC
magnetic field sensitivity of VB– ensemble is significantly improved
up to 2.87 ± 0.07 μT/Hz. Our results provide important suggestions
for further applications of VB– centers in quantum information processing
and ODMR-based quantum sensing.