Ultra-high dynamic range quantum measurement retaining its sensitivity

E D Herbschleb,N Mizuochi,T Makino,S Yamasaki,H Kato

doi:10.1038/s41467-020-20561-x

Abstract

Quantum sensors are highly sensitive since they capitalise on fragile quantum properties such as coherence, while enabling ultra-high spatial resolution. For sensing, the crux is to minimise the measurement uncertainty in a chosen range within a given time. However, basic quantum sensing protocols cannot simultaneously achieve both a high sensitivity and a large range. Here, we demonstrate a non-adaptive algorithm for increasing this range, in principle without limit, for alternating-current field sensing, while being able to get arbitrarily close to the best possible sensitivity. Therefore, it outperforms the standard measurement concept in both sensitivity and range. Also, we explore this algorithm thoroughly by simulation, and discuss the T−2 scaling that this algorithm approaches in the coherent regime, as opposed to the T−1/2 of the standard measurement. The same algorithm can be applied to any modulo-limited sensor.

Highlights

Quantum sensors are highly sensitive since they capitalise on fragile quantum properties such as coherence, while enabling ultra-high spatial resolution
An increase in sensitivity can be gained for alternating current (AC) field sensing by prolonging the NV spin coherence with dynamical decoupling of the centre’s spin from its environment[2,3,9,10,11,12]
Both a wide range of the AC field amplitude and a high sensitivity are very important, because the magnitude of the AC field strongly depends on the distance r from the NV spin (r−3 in case of a magnetic dipole field)

Summary

Introduction

Quantum sensors are highly sensitive since they capitalise on fragile quantum properties such as coherence, while enabling ultra-high spatial resolution. A standard Hahn-echo sequence is performed over the full period of the magnetic field (Fig. 1b, for single NV centres this period should be shorter than about half the coherence time[3]).

Results

Conclusion