Excited-State Spectroscopy of Spin Defects in Hexagonal Boron Nitride

A negatively charged boron vacancy (VB-) color center inhexagonal boron nitride has recently been proposed as a promisingquantum sensor due to its excellent properties. However, the spin levelstructure of the VB-color center is still unclear, especially for the excitedstate. Here we measured and confirmed the excited-state spin transitions ofVB-using an optically detected magnetic resonance (ODMR) technique.The zero-field splitting of the excited state is 2.06 GHz, the transversesplitting is 93.1 MHz, and thegfactor is 2.04. Moreover, negative peaks influorescence intensity and ODMR contrast at the level anticrossing pointwere observed, and they further confirmed that the spin transitions wemeasured came from the excited state. Our work deepens the under-standing of the excited-state structure of VB-and promotes VB--based quantum sensing applications

Automated summary

The excited-state spin transitions of a negatively charged boron vacancy (VB-) color center in hexagonal boron nitride were measured and characterized using an optically detected magnetic resonance (ODMR) technique. The study provides insights into the excited-state structure of VB- and its potential applications in quantum sensing.