Charge state dynamics of the nitrogen vacancy center in diamond under 1064 nm laser excitation

TL;DR

This study reveals that 1064 nm laser excitation induces charge state conversion in NV centers in diamond, with spin-dependent dynamics, advancing understanding of their photophysics under near-infrared light.

Contribution

It demonstrates for the first time that 1064 nm laser causes NV center charge conversion via valence band absorption, with spin-dependent effects and fast photoluminescence dynamics.

Findings

NV$^{0}$ converts to NV$^{-}$ under 1064 nm excitation

Charge transfer process is spin-dependent

Fast quenching and recovery of photoluminescence observed

Abstract

The photophysics and charge state dynamics of the nitrogen vacancy (NV) center in diamond has been extensively investigated but is still not fully understood. In contrast to previous work, we find that NV$^{0}$ converts to NV$^{-}$ under excitation with low power near-infrared (1064 nm) light, resulting in $increased$ photoluminescence from the NV$^{-}$ state. We used a combination of spectral and time-resolved photoluminescence experiments and rate-equation modeling to conclude that NV$^{0}$ converts to NV$^{-}$ via absorption of 1064 nm photons from the valence band of diamond. We report fast quenching and recovery of the photoluminescence from $both$ charge states of the NV center under low power 1064 nm laser excitation, which has not been previously observed. We also find, using optically detected magnetic resonance experiments, that the charge transfer process mediated by the 1064 nm laser is spin-dependent.