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

Understand

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.