Fig. 1: Quantum sensing using \({V}_{{{{{{\rm{B}}}}}}}^{-}\) spin defects in hexagonal boron nitride (hBN).
From: Wide field imaging of van der Waals ferromagnet Fe3GeTe2 by spin defects in hexagonal boron nitride
a Schematic of a Fe3GeTe2(FGT)/hBN van der Waals heterostructure transferred onto an Au microwave stripline for wide-field magnetometry measurements. b Optical microscope image of a prepared FGT/hBN device. The FGT and hBN flakes are outlined with red and black dashed lines, respectively. The scale bar is 5 \({{{{{\rm{\mu }}}}}}\)m. c Schematic of \({V}_{{{{{{\rm{B}}}}}}}^{-}\) spin defects (blue arrows) formed in a hexagonal crystalline structure with alternating boron (red) and nitrogen (green) atoms. A negatively charged boron atom vacancy \({V}_{{{{{{\rm{B}}}}}}}^{-}\) is surrounded by three nitrogen atoms located in the nearest neighboring sites. d Energy level diagram of a \({V}_{{{{{{\rm{B}}}}}}}^{-}\) spin defect and schematic illustration of optical excitation (green arrow), radiative recombination (red arrow), and nonradiative decay (black dotted arrow) processes between the ground state (GS), excited state (ES), and metastable state (MS). e Top panel: optical and microwave sequence of pulsed optically detected magnetic resonance (ODMR) measurements. Bottom panel: ODMR spectra of \({V}_{{{{{{\rm{B}}}}}}}^{-}\) spin defects measured at a series of perpendicularly applied external magnetic fields Bext. f Top panel: optical and microwave sequence of spin relaxometry measurements. Bottom panel: a set of spin relaxometry data of \({V}_{{{{{{\rm{B}}}}}}}^{-}\) spin defects showing spin dependent photoluminescence measured as a function of delay time t. The external magnetic field is 185 G applied along the out-of-plane direction, and the measurement temperature is 295 K.
