# Discovery of ST1 centers in natural diamond

## TL;DR

This paper reports the discovery of ST1 centers in natural diamond, revealing their optical properties and electronic structure, which are promising for quantum computing applications due to their high contrast and minimal decoherence.

## Contribution

The study identifies ST1 centers in natural diamond, characterizes their optical and electronic properties, and proposes potential chemical structures based on combined experimental and theoretical analysis.

## Key findings

- Power dependence of optical dynamics observed
- New electronic structure details revealed
- Likely chemical structures shortlisted

## Abstract

The ST1 center is a point defect in diamond with bright fluorescence and a mechanism for optical spin initialization and readout. The center has impressive potential for applications in diamond quantum computing as a quantum bus to a register of nuclear spins. This is because it has an exceptionally high readout contrast and, unlike the well-known nitrogen-vacancy center, it does not have a ground state electronic spin that decoheres the nuclear spins. However, its chemical structure is unknown and there are large gaps in our understanding of its properties. We present the discovery of ST1 centers in natural diamond. Our experiments identify interesting power dependence of the center's optical dynamics and reveal new electronic structure. We also present a theory of its electron-phonon interactions, which we combine with previous experiments, to shortlist likely candidates for its chemical structure.