Theory of neutral nitrogen-vacancy center in diamond and its qubit application

TL;DR

This paper identifies the neutral nitrogen-vacancy center (NV$^0$) in diamond as a promising qubit candidate, capable of optical spin initialization, manipulation, and readout without nitrogen donors, expanding quantum computing possibilities.

Contribution

The study unambiguously characterizes NV$^0$ using ab initio calculations, demonstrating its potential as a nitrogen-donor-free qubit in diamond.

Findings

NV$^0$ can be optically selectively spin-occupied

Electron spin in NV$^0$ can be manipulated by magnetic fields

NV$^0$ spin states can be optically read out

Abstract

The negatively charged nitrogen-vacancy defect (NV)$^-$ in diamond has attracted much attention in recent years in qubit and biological applications. The negative charge is donated from nearby nitrogen donors that could limit or stem the successful application of (NV)$^-$. In this Letter, we unambiguously identify the \emph{neutral} nitrogen-vacancy defect (NV$^0$) by \emph{ab initio} supercell calculations. Our analysis shows that i) the spin state can be \emph{selectively} occupied optically, ii) the electron spin state can be manipulated by time-varying magnetic field, and iii) the spin state may be read out optically. Based on this NV$^0$ is a new hope for realizing qubit in diamond \emph{without} the need of nitrogen donors.