Spin-dependent quantum emission from defects in hexagonal boron nitride

Abstract

Optically addressable spins associated with localized defects in wide-bandgap semiconductors are the basis for rapidly expanding quantum technologies in nanoscale sensing and quantum information processing. Whereas most research has focused on three-dimensional host materials such as diamond, the van der Waals material hexagonal boron nitride (hBN) has emerged as a robust host for bright, stable, room-temperature quantum emitters (QEs). I will discuss recent experiments that reveal the role of spin for QEs in hBN. Select QEs exhibit striking, anisotropic modulation of emission in response to an applied magnetic field, consistent with optical dynamics featuring a spin-dependent inter-system crossing between singlet and triplet spin states. Many questions persist regarding the chemical and electronic structure of these QEs, which generally exhibit widely heterogeneous optical characteristics, and ongoing work aims to elucidate their formation and stabilization mechanisms. Nonetheless, the discovery of optically addressable spins in room-temperature h-BN ushers in a new platform for spin-based quantum technologies with the potential for atom-scale engineering and versatile functionality.