Optical patterning of trapped charge in nitrogen-doped diamond

TL;DR

This paper investigates how optical methods can manipulate and pattern trapped charge in nitrogen-doped diamond, revealing spatial charge distributions and dynamics relevant for quantum information and memory applications.

Contribution

It introduces a two-color optical microscopy technique to control and visualize charge patterns in NV centers, advancing understanding of charge dynamics in diamond.

Findings

Formation of spatial trapped charge patterns observed.

Charge redistribution can be locally controlled with laser excitation.

Mapping of positively charged nitrogen fraction demonstrates charge manipulation.

Abstract

The nitrogen-vacancy (NV) centre in diamond is emerging as a promising platform for solid-state quantum information processing and nanoscale metrology. Of interest in these applications is the manipulation of the NV charge, which can be attained by optical excitation. Here we use two-color optical microscopy to investigate the dynamics of NV photo-ionization, charge diffusion, and trapping in type-1b diamond. We combine fixed-point laser excitation and scanning fluorescence imaging to locally alter the concentration of negatively charged NVs, and to subsequently probe the corresponding redistribution of charge. We uncover the formation of spatial patterns of trapped charge, which we qualitatively reproduce via a model of the interplay between photo-excited carriers and atomic defects. Further, by using the NV as a probe, we map the relative fraction of positively charged nitrogen upon localized optical excitation. These observations may prove important to transporting quantum information between NVs or to developing three-dimensional, charge-based memories.