Integrable quantum many-body sensors for AC field sensing

TL;DR

This paper demonstrates that integrable quantum many-body systems can be used for highly precise AC field sensing by exploiting their dynamics and partial subsystem access, surpassing classical limits and approaching the Heisenberg bound.

Contribution

It introduces a novel protocol utilizing integrable many-body dynamics and partial measurements for enhanced AC field sensing, applicable to near-term quantum simulators.

Findings

Achieves sensing precision beyond classical limits.

Utilizes local block steady states for measurement.

Compatible with near-term quantum devices like ion traps.

Abstract

Quantum sensing is inevitably an elegant example of the supremacy of quantum technologies over their classical counterparts. One of the desired endeavors of quantum metrology is AC field sensing. Here, by means of analytical and numerical analysis, we show that integrable many-body systems can be exploited efficiently for detecting the amplitude of an AC field. Unlike the conventional strategies in using the ground states in critical many-body probes for parameter estimation, we only consider partial access to a subsystem. Due to the periodicity of the dynamics, any local block of the system saturates to a steady state which allows achieving sensing precision well beyond the classical limit, almost reaching the Heisenberg bound. We associate the enhanced quantum precision to closing of the Floquet gap, resembling the features of quantum sensing in the ground state of critical systems. We show that the proposed protocol can also be realized in near-term quantum simulators, e.g. ion-traps, with a limited number of qubits. We show that in such systems a simple block magnetization measurement and a Bayesian inference estimator can achieve very high precision AC field sensing.