Robust quantum sensing in strongly interacting systems with many-body scars

TL;DR

This paper demonstrates that quantum many-body scars can be utilized to achieve robust quantum sensing in strongly interacting systems, preventing thermalisation and maintaining high sensitivity.

Contribution

It introduces a novel approach to quantum sensing leveraging many-body scars, showing how they can counteract interaction-induced thermalisation.

Findings

Perfect scars with harmonic energy gaps enable diverging optimal sensing time.

Two models exemplify scar-based sensing: a spin-1 model with Dzyaloshinskii-Moriya interaction and a spin-1/2 Ising model.

Periodic controls can mitigate non-ideal perturbations affecting sensing.

Abstract

In most quantum sensing schemes, interactions between the constituent particles of the sensor are expected to lead to thermalisation and degraded sensitivity. However, recent theoretical and experimental work has shown that the phenomenon of quantum many-body scarring can slow down, or even prevent thermalisation. We show that scarring can be exploited for quantum sensing that is robust against certain strong interactions. In the ideal case of perfect scars with harmonic energy gaps, the optimal sensing time can diverge despite the strong interactions. We demonstrate the idea with two examples: a spin-1 model with Dzyaloshinskii-Moriya interaction, and a spin-1/2 mixed-field Ising model. We also briefly discuss some non-ideal perturbations, and the addition of periodic controls to suppress their effect on sensing.