NV centers in3C,4H, and6Hsilicon carbide: A variable platform for solid-state qubits and nanosensors

Abstract

The outstanding magneto-optical properties of the nitrogen-vacancy (NV) center in diamond have stimulated the search for similar systems. We show here that NV triplet centers can also be generated in all the main SiC polytypes. We have identified by electron paramagnetic resonance spectroscopy and first-principles calculations the axial ${\mathrm{NV}}^{\ensuremath{-}}$ pairs in $3C,4H$, and $6H$ SiC, showing polytype and lattice site-specific magnetic and optical properties. We demonstrate very efficient room-temperature spin polarization of the ground state upon near infrared optical excitation for the NV center in $3C$ SiC and axial NV centers in the hexagonal $(4H,6H)$ polytypes; the signals of basal pairs are much lower in intensity. Axial NV centers in hexagonal SiC polytypes and thus constitute unidirectional ensembles which may be useful in nanosensing applications.