Highly-tunable formation of nitrogen-vacancy centers via ion implantation

TL;DR

This paper presents a method for precisely creating nitrogen-vacancy centers in diamond using ion implantation through nanoscale apertures, enabling controlled placement and consistent properties for quantum applications.

Contribution

The study introduces a tunable ion implantation technique with high spatial resolution to deterministically control NV center formation and properties in diamond.

Findings

Ion-to-NV conversion yield of 6-7% across various parameters

Achieved spin dephasing times comparable to natural NV centers (~3 microseconds)

Controlled NV population distribution for quantum device integration

Abstract

We demonstrate highly-tunable formation of nitrogen-vacancy (NV) centers using 20 keV 15N+ ion implantation through arrays of high-resolution apertures fabricated with electron beam lithography. By varying the aperture diameters from 80 to 240 nm, as well as the average ion fluences from 5 x 10^10 to 2 x 10^11 ions/cm^2, we can control the number of ions per aperture. We analyze the photoluminescence on multiple sites with different implantation parameters and obtain ion-to-NV conversion yields of 6 to 7%, consistent across all ion fluences. The implanted NV centers have spin dephasing times T2* ~ 3 microseconds, comparable to naturally occurring NV centers in high purity diamond with natural abundance 13C. With this technique, we can deterministically control the population distribution of NV centers in each aperture, allowing for the study of single or coupled NV centers and their integration into photonic structures.