Spin-polarization of VGaON center in GaN and its application in spin qubit

Abstract

VGaON center in cubic gallium nitride is a defect complex composing of a substitutional oxygen atom at nitrogen site (ON) and an adjacent gallium vacancy (VGa). Based on first-principles calculations, we predicted that this VGaON center has much in common with the famous nitrogen-vacancy center in diamond, but the excitation energy is very low. The electron spin-polarization of the centers can be tuned by changing the charge states. The neutral ONVGa center has the v↓ and exy↓ states being well isolated from the bulk bands with appropriate spacing which are suitable for achieving spin qubit operation with low excitation energy.