Quantum point defects in 2D materials: The QPOD database

TL;DR

This paper introduces the QPOD database, a comprehensive collection of quantum defect data in 2D materials, generated through DFT calculations, to facilitate quantum technology research.

Contribution

The paper presents the creation of a large, publicly accessible database of quantum defects in 2D materials, including detailed computational data and analysis workflows.

Findings

Identification of promising defects for quantum applications

Analysis of defect tolerance and dopability in 2D hosts

Provision of a web-accessible database for researchers

Abstract

Atomically thin two-dimensional (2D) materials are ideal hosts of quantum defects as they offer easier control, manipulation and read-out of defect states compared to bulk systems. Here we introduce the Quantum Point Defect (QPOD) database of more than 1900 defect systems with 503 unique intrinsic point defects (vacancies and antisites) in 82 2D insulators. The Atomic Simulation Recipes (ASR) workflow framework was used to perform density functional theory (DFT) calculations of defect formation energies, charge transition levels, Fermi level positions, equilibrium defect and carrier concentrations, transition dipole moments, hyperfine coupling, and zero-field splitting. Excited states and photoluminescence spectra were calculated for selected high-spin defects. In this paper we describe the calculations and workflow behind the QPOD database, present an overview of its content, and discuss some general trends and correlations in the data. We analyse the degree of defect tolerance as well as intrinsic dopability of the host materials and identify promising defects for quantum technological applications. The database is freely available and can be browsed via a web-app interlinked with the Computational 2D Materials Database (C2DB).