# Observation of an environmentally insensitive solid state spin defect in diamond

## TL;DR

This paper reports a new silicon vacancy defect in diamond, SiV0, that is highly resistant to environmental decoherence, with long coherence times and excellent optical properties, advancing solid-state quantum systems.

## Contribution

The study introduces SiV0 as an environmentally insensitive solid-state spin defect with exceptional coherence and optical properties, achieved through material engineering.

## Key findings

- Spin-lattice relaxation time (T1) approaches one minute.
- Coherence time (T2) approaches one second.
- Approximately 90% of emission into the zero-phonon line.

## Abstract

Engineering coherent systems is a central goal of quantum science. Color centers in diamond are a promising approach, with the potential to combine the coherence of atoms with the scalability of a solid state platform. However, the solid environment can adversely impact coherence. For example, phonon- mediated spin relaxation can induce spin decoherence, and electric field noise can change the optical transition frequency over time. We report a novel color center with insensitivity to both of these sources of environmental decoherence: the neutral charge state of silicon vacancy (SiV0). Through careful material engineering, we achieve over 80% conversion of implanted silicon to SiV0. SiV0 exhibits excellent spin properties, with spin-lattice relaxation times (T1) approaching one minute and coherence times (T2) approaching one second, as well as excellent optical properties, with approximately 90% of its emission into the zero-phonon line and near-transform limited optical linewidths. These combined properties make SiV0 a promising defect for quantum networks.

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Source: https://tomesphere.com/paper/1706.01555