# Temperature dependence of the $^{13}$C hyperfine structure of the negatively-charged nitrogen-vacancy center in diamond

## TL;DR

This study investigates how the hyperfine interactions of the NV center in diamond vary with temperature from 10 K to 700 K, revealing minimal changes and insights into the defect's electronic structure and stability.

## Contribution

It provides detailed experimental and theoretical analysis of temperature effects on the $^{13}$C hyperfine structure in NV centers, enhancing understanding for quantum sensing applications.

## Key findings

- Hyperfine interaction change is small across temperature range
- Changes are mainly due to orbital hybridization variations
- Defect structure tends toward undistorted at higher temperatures

## Abstract

The nitrogen-vacancy (NV) center is a well utilized system for quantum technology, in particular quantum sensing and microscopy. Fully employing the NV center's capabilities for metrology requires a strong understanding of the behavior of the NV center with respect to changing temperature. Here, we probe the NV electronic spin density as the surrounding crystal temperature changes from 10 K to 700 K by examining its $^{13}$C hyperfine interactions. These results are corroborated with \textit{ab initio} calculations and demonstrate that the change in hyperfine interaction is small and dominated by a change in the hybridization of the orbitals constituting the spin density. Thus indicating that the defect and local crystal geometry is returning towards an undistorted structure at higher temperature.