Photochromism in single nitrogen-vacancy defect in diamond

TL;DR

This paper demonstrates photochromism in single nitrogen-vacancy centers in diamond, showing charge state switching under light and dark conditions, with implications for quantum applications.

Contribution

It provides the first direct evidence of photochromism in single NV centers and explores the underlying mechanism involving nitrogen donors.

Findings

Intense 514 nm irradiation switches NV centers to negative charge state.

The defect relaxes back to neutral in dark conditions.

Photon emission from different charge states confirms charge state dynamics.

Abstract

Photochromism in single nitrogen-vacancy optical centers in diamond is demonstrated. Time-resolved optical spectroscopy shows that intense irradiation at 514 nm switches the nitrogen-vacancy defects to the negative form. This defect state relaxes back to the neutral form under dark conditions. Temporal anticorrelation of photons emitted by the different charge states of the optical center unambiguously indicates that the nitrogen-vacancy defect accounts for both 575 nm and 638 nm emission bands. Possible mechanism of photochromism involving nitrogen donors is discussed.