Scalable Focused Ion Beam Creation of Nearly Lifetime-Limited Single Quantum Emitters in Diamond Nanostructures

TL;DR

This paper demonstrates a precise, scalable method to create nearly lifetime-limited single quantum emitters in diamond nanostructures using focused ion beam implantation, advancing quantum photonic device development.

Contribution

It introduces a maskless, high-precision technique for creating coherent single SiV centers in diamond nanostructures with improved yield and optical properties.

Findings

Achieved ~32 nm lateral precision in SiV center placement.

Observed near lifetime-limited emission linewidths (~126 MHz).

Enhanced conversion yield with electron irradiation.

Abstract

The controlled creation of defect center---nanocavity systems is one of the outstanding challenges for efficiently interfacing spin quantum memories with photons for photon-based entanglement operations in a quantum network. Here, we demonstrate direct, maskless creation of atom-like single silicon-vacancy (SiV) centers in diamond nanostructures via focused ion beam implantation with $\sim 32$ nm lateral precision and $< 50$ nm positioning accuracy relative to a nanocavity. Moreover, we determine the Si+ ion to SiV center conversion yield to $\sim 2.5\%$ and observe a 10-fold conversion yield increase by additional electron irradiation. We extract inhomogeneously broadened ensemble emission linewidths of $\sim 51$ GHz, and close to lifetime-limited single-emitter transition linewidths down to $126 \pm13$ MHz corresponding to $\sim 1.4$-times the natural linewidth. This demonstration of deterministic creation of optically coherent solid-state single quantum systems is an important step towards development of scalable quantum optical devices.