Robust entanglement-based magnetic field sensor beyond the standard quantum limit

TL;DR

This paper demonstrates a practical entanglement-based magnetic field sensor capable of surpassing the standard quantum limit despite decoherence, using realistic entangled states achievable with current technology.

Contribution

It introduces a method to overcome decoherence limitations in entanglement-based quantum sensing, enabling practical magnetic field measurements beyond the standard quantum limit.

Findings

Achieves magnetic field sensing beyond the standard quantum limit under decoherence.

Uses realistic entangled states that are feasible with current technology.

Provides a pathway for practical entanglement-based quantum sensors.

Abstract

Recently, there have been significant developments in entanglement-based quantum metrology. However, entanglement is fragile against experimental imperfections, and quantum sensing to beat the standard quantum limit in scaling has not yet been achieved in realistic systems. Here, we show that it is possible to overcome such restrictions so that one can sense a magnetic field with an accuracy beyond the standard quantum limit even under the effect of decoherence, by using a realistic entangled state that can be easily created even with current technology. Our scheme could pave the way for the realizations of practical entanglement-based magnetic field sensors.