Semiempirical $\textit{ab initio}$ modeling of bound states of deep defects in semiconductor quantum technologies

TL;DR

This paper introduces a semi-ab initiobb modeling approach for deep defect bound states in semiconductors, specifically applied to NV centers in diamond, improving understanding of charge dynamics crucial for quantum tech.

Contribution

It develops a semi-ab initiobb method combining DFT and effective mass models to accurately simulate deep defect states and charge transitions in semiconductors.

Findings

Model accurately predicts bound hole states in NV centers

Nonradiative capture cross sections match experimental data within one order of magnitude

Bound hole electronic transitions can be distinguished from phonon sidebands

Abstract

A significant hurdle in developing high-performance semiconductor quantum technologies utilizing deep defects is related to charge dynamics. Unfortunately, progress in modeling their charge dynamics has been hindered over recent decades due to the absence of appropriate multiscale models capable of accurately representing the atomic properties of these defects and their impact on device performance. Here, we present a semi-\textit{ab initio} method for modeling the bound states of deep defects in semiconductor quantum technologies, applied to the negatively charged nitrogen vacancy (NV$^-$) center in diamond. We employ density functional theory calculations to construct accurate potentials for an effective mass model, which allow us to unveil the structure of the bound hole states. We develop a model to calculate the nonradiative capture cross sections, which agrees with experiment within one order of magnitude. Finally, we present our attempt at constructing the photoionization spectrum of NV$^0\rightarrow$ NV$^-$ + bound hole, showing that the electronic transitions of the bound holes can be distinguished from phonon sidebands. This paper offers a practical and efficient solution to a long-standing challenge in understanding the charge dynamics of deep defects.