Quantum electrometry of non-volatile space charges in diamond

TL;DR

This paper demonstrates quantum electrometry in diamond to observe stable space charge distributions caused by trapped charges, revealing how optical illumination and electric fields influence charge dynamics and material properties.

Contribution

It introduces a method for quantum electrometry in diamond to visualize and analyze space charge distributions from trapped charges, advancing understanding of charge behavior in wide-bandgap semiconductors.

Findings

Space charges grow under optical illumination and electric fields.

Space charge fields originate from dispersed nitrogen charges.

Charge distributions can screen applied electric fields over tens of microns.

Abstract

The microscopic electric environment surrounding a spin defect in a wide-bandgap semiconductor plays a determining role in the spin coherence and charge stability of a given qubit and has an equally important role in defining the electrical properties of the host material. Here, we use electrometry of quantum defects embedded within a diamond to observe stable, micron-scale space charge distributions formed from trapped photogenerated charges. These space charges grow under optical illumination in the presence of an applied electric field, eventually screening the applied electric field entirely over a spatial extent of tens of microns due to charge carrier drift and capture. Our measurements suggest that these space charge fields originate from widely-dispersed spatial configurations of nitrogen charges. Our results have important consequences for electrometry and photoelectric detection using qubits in wide-bandgap semiconductors.