arXiv:1204.4898 · Physical Review Letters
Optically Controlled Switching of the Charge State of a Single Nitrogen-Vacancy Center in Diamond at Cryogenic Temperatures
Petr Siyushev, Hugo Pinto, Márton Vörös, Ádám Gali, Fedor Jelezko, Jörg Wrachtrup
Abstract
In this Letter, the photoinduced switching of the single nitrogen-vacancy (NV) center between two different charge states, negative (${\mathrm{NV}}^{\ensuremath{-}}$) and neutral (${\mathrm{NV}}^{0}$), is studied under resonant excitation at liquid helium temperature. We show that resonant conversion of ${\mathrm{NV}}^{0}$ to ${\mathrm{NV}}^{\ensuremath{-}}$ significantly improves spectral stability of the ${\mathrm{NV}}^{\ensuremath{-}}$ defect and allows high fidelity initialization of the spin qubit. Based on density functional theory calculations a novel mechanism involving an Auger ionization of ${\mathrm{NV}}^{\ensuremath{-}}$ and charge transfer of an electron from the valence band to ${\mathrm{NV}}^{0}$ is discussed. This study provides further insight into the charge dynamics of the NV center, which is relevant for quantum information processing based on an ${\mathrm{NV}}^{\ensuremath{-}}$ defect in diamond.