# Optimizing the formation of depth-confined nitrogen vacancy center spin ensembles in diamond for quantum sensing

## TL;DR

This paper investigates how to optimize the creation of depth-confined nitrogen vacancy (NV) center ensembles in diamond to enhance their magnetic sensitivity for quantum sensing applications.

## Contribution

It introduces a method to engineer NV ensembles with near-optimal magnetic sensitivity by controlling growth and irradiation parameters in diamond layers.

## Key findings

- NV ensembles achieve sensitivity close to the dipolar interaction limit
- Depth confinement improves NV ensemble stability
- Optimized parameters enhance quantum sensing performance

## Abstract

Spin ensembles of nitrogen vacancy (NV) centers in diamond are emerging as powerful spin-based sensors for magnetic, electric and thermal field imaging with high spatial and temporal resolution. Here we characterize the formation of depth-confined NV center ensembles, activated by electron irradiation in diamond layers grown by plasma enhanced chemical vapor deposition with nitrogen co-doping. To do so, we exploit the high magnetic sensitivity of ensembles of NV centers to probe their spin environment as a function of growth and irradiation parameters. We engineer an NV ensemble whose magnetic sensitivity is within a factor of two of the static NV-NV dipolar interaction limit, thus demonstrating a powerful platform for quantum sensing.