Excited-State Spectroscopy of Spin Defects in Hexagonal Boron Nitride

Pei Yu; Haoyu Sun; Mengqi Wang; Tao Zhang; Xiangyu Ye; Jingwei Zhou; Hangyu Liu; Cheng-Jie Wang; Fazhan Shi; Ya Wang; Jiangfeng Du

doi:10.1021/acs.nanolett.1c04841

Excited-State Spectroscopy of Spin Defects in Hexagonal Boron Nitride

Nano Lett. 2022 May 11;22(9):3545-3549. doi: 10.1021/acs.nanolett.1c04841. Epub 2022 Apr 19.

Authors

Pei Yu^{1

2}, Haoyu Sun^{1

2}, Mengqi Wang^{1

2}, Tao Zhang^{1

2}, Xiangyu Ye^{1

2}, Jingwei Zhou^{1

2}, Hangyu Liu^{1

2}, Cheng-Jie Wang^{1

2}, Fazhan Shi^{1

2}, Ya Wang^{1

2}, Jiangfeng Du^{1

2}

Affiliations

¹ CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, People's Republic of China.
² CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.

PMID: 35439014
DOI: 10.1021/acs.nanolett.1c04841

Abstract

A negatively charged boron vacancy (V_B^-) color center in hexagonal boron nitride has recently been proposed as a promising quantum sensor due to its excellent properties. However, the spin level structure of the V_B^- color center is still unclear, especially for the excited state. Here we measured and confirmed the excited-state spin transitions of V_B^- using an optically detected magnetic resonance (ODMR) technique. The zero-field splitting of the excited state is 2.06 GHz, the transverse splitting is 93.1 MHz, and the g factor is 2.04. Moreover, negative peaks in fluorescence intensity and ODMR contrast at the level anticrossing point were observed, and they further confirmed that the spin transitions we measured came from the excited state. Our work deepens the understanding of the excited-state structure of V_B^- and promotes V_B^--based quantum sensing applications.

Keywords: color center; excited state; hexagonal boron nitride; optically detected magnetic resonance.