Discovery of T center-like quantum defects in silicon

TL;DR

This study identifies new T center-like quantum defects in silicon using high-throughput computational screening, which could serve as efficient single-photon emitters or spin-photon interfaces for quantum technologies.

Contribution

The paper introduces a new family of T center-like defects in silicon discovered through computational screening, with potential advantages over existing centers.

Findings

Defects are analogous to the T center in structure and electronic properties.

Some defects show improved radiative lifetime and emission efficiency.

Hydrogenated defects can be synthesized via annealing and dehydrogenation.

Abstract

Quantum technologies would benefit from the development of high performance quantum defects acting as single-photon emitters or spin-photon interface. Finding such a quantum defect in silicon is especially appealing in view of its favorable spin bath and high processability. While some color centers in silicon have been emerging in quantum applications, there is still a need to search and develop new high performance quantum emitters. Searching a high-throughput computational database of more than 22,000 charged complex defects in silicon, we identify a series of defects formed by a group III element combined with carbon ((A-C)$\rm _{Si}$ with A=B,Al,Ga,In,Tl) and substituting on a silicon site. These defects are analogous structurally, electronically and chemically to the well-known T center in silicon ((C-C-H)$\rm_{Si}$) and their optical properties are mainly driven by an unpaired electron in a carbon $p$ orbital. They all emit in the telecom and some of these color centers show improved properties compared to the T center in terms of computed radiative lifetime or emission efficiency. We also show that the synthesis of hydrogenated T center-like defects followed by a dehydrogenation annealing step could be an efficient way of synthesis. All the T center-like defects show a higher symmetry than the T center making them easier to align with magnetic fields. Our work motivates further studies on the synthesis and control of this new family of quantum defects, and also demonstrates the use of high-throughput computational screening to detect new complex quantum defects.