Magnetic field-assisted spectral decomposition and imaging of charge states of NV centers in diamond

TL;DR

This paper introduces two spectroscopy-based methods to map and distinguish charge states of NV centers in diamond, aiding quantum technology applications by revealing their spatial charge distribution.

Contribution

It presents novel spectral decomposition and optical filtering techniques for imaging NV charge states, enhancing understanding of their charge dynamics in diamond.

Findings

Successfully decomposed NV spectra into charge states using magnetic field effects.

Achieved spatial mapping of NV$^-$ and NV$^0$ charge states in diamond.

Demonstrated optical filter-based PL imaging for charge state identification.

Abstract

With the advent of quantum technology, nitrogen vacancy ($NV$) centers in diamond turn out to be a frontier which provides an efficient platform for quantum computation, communication and sensing applications. Due to the coupled spin-charge dynamics of the $NV$ system, knowledge about $NV$ charge state dynamics can help to formulate efficient spin control sequences strategically. Through this paper we report two spectroscopy-based deconvolution methods to create charge state mapping images of ensembles of $NV$ centers in diamond. First, relying on the fact that an off axis external magnetic field mixes the electronic spins and selectively modifies the photoluminescence (PL) of $NV^-$, we perform decomposition of the optical spectrum for an ensemble of $NV$s and extract the spectra for $NV^-$ and $NV^0$ states. Next, we introduce an optical filter based decomposition protocol and perform PL imaging for $NV^-$ and $NV^0$. Earlier obtained spectra for $NV^-$ and $NV^0$ states are used to calculate their transmissivities through a long pass optical filter. These results help us to determine the spatial distribution of the $NV$ charge states in a diamond sample.