Fluorescence thermometry enhanced by the quantum coherence of single spins in diamond

TL;DR

This paper presents advanced fluorescence thermometry using nitrogen vacancy centers in diamond, achieving high sensitivity by leveraging quantum coherence and dynamical decoupling to improve temperature measurement precision.

Contribution

It introduces a novel thermometry method that significantly enhances sensitivity and coherence times of NV centers through dynamical decoupling protocols, enabling practical applications across various environments.

Findings

Achieved temperature sensitivities approaching 10 mK/Hz^{1/2}

Enhanced spin coherence times by 45 times using dynamical decoupling

Demonstrated broad temperature range applicability in different magnetic fields

Abstract

We demonstrate fluorescence thermometry techniques with sensitivities approaching 10 mK Hz^(-1/2) based on the spin-dependent photoluminescence of nitrogen vacancy (NV) centers in diamond. These techniques use dynamical decoupling protocols to convert thermally induced shifts in the NV center's spin resonance frequencies into large changes in its fluorescence. By mitigating interactions with nearby nuclear spins and facilitating selective thermal measurements, these protocols enhance the spin coherence times accessible for thermometry by 45x, corresponding to a 7x improvement in the NV center's temperature sensitivity. Moreover, we demonstrate these techniques can be applied over a broad temperature range and in both finite and near-zero magnetic field environments. This versatility suggests that the quantum coherence of single spins could be practically leveraged for sensitive thermometry in a wide variety of biological and microscale systems.