1 research outputs found
Exploring the Properties of the V_B^- Defect in hBN: Optical Spin Polarization, Rabi Oscillations, and Coherent Nuclei Modulation
Optically active point defects in semiconductors have received great
attention in the field of solid-state quantum technologies. Hexagonal boron
nitride, with an ultra-wide band gap E_g = 6 eV, containing a negatively
charged boron vacancy (V_B^-) with unique spin, optical, and coherent
properties presents a new two-dimensional platform for the implementation of
quantum technologies. This work establishes the value of V_B^ - spin
polarization under optical pumping with {\lambda}ext = 532 nm laser using
high-frequency ({\nu}mw = 94 GHz) electron paramagnetic resonance (EPR)
spectroscopy. In optimal conditions polarization was found to be P = 38.4 %.
Our study reveals that Rabi oscillations induced on polarized spin states
persist for up to 30-40 microseconds, which is nearly two orders of magnitude
longer than what was previously reported. Analysis of the coherent
electron-nuclear interaction through the observed electron spin echo envelope
modulation (ESEEM) made it possible to detect signals from remote nitrogen and
boron nuclei, and to establish a corresponding quadrupole coupling constant Cq
= 180 kHz related to nuclear quadrupole moment of 14N. These results have
fundamental importance for understanding spin properties of boron vacancy