Robust and efficient control of spin probes in a complex (biological) environment. Towards sensing of fast temperature fluctuations

TL;DR

This paper introduces an optimized control scheme combining Ramsey measurement and optimal control theory for nanoscale temperature sensing using nitrogen-vacancy centers in nanodiamonds, enabling detection of rapid temperature fluctuations in complex biological environments.

Contribution

It develops a universal, efficient control method that improves temperature readout accuracy in complex environments, surpassing traditional control pulses.

Findings

Enhanced readout signal with optimized control pulses

Successful temperature measurement in biological matrices

Potential for sensing other physical quantities

Abstract

We present an optimized scheme for nanoscale measurements of temperature in a complex environment using the nitrogen-vacancy center in nanodiamonds. To this end we combine a Ramsey measurement utilized to temperature determination with advanced optimal control theory. We test our new design on single nitrogen-vacancy centers in bulk diamond and fixed nanodiamonds, achieving better readout signal than with common soft or hard microwave control pulses. We demonstrate temperature readout using rotating nanodiamonds in an agarose matrix. Our method opens the way to measure temperature fluctuations in complex biological environment. The used principle however, is universal and not restricted to temperature sensing.