Entanglement-assist cyclic weak-value-amplification metrology

TL;DR

This paper explores how combining entanglement with power recycling cavities enhances weak measurement sensitivity and efficiency, addressing error impacts and optimizing measurement accuracy.

Contribution

It introduces a novel entanglement-assisted weak measurement scheme with power recycling, improving detection efficiency and Fisher information beyond previous methods.

Findings

Entanglement and recycling improve measurement in different dimensions.

Power recycling enhances Fisher information and measurement accuracy.

Entanglement can worsen walk-off errors, but proper parameters mitigate this.

Abstract

Weak measurement has garnered widespread interest for its ability to amplify small physical effects at the cost of low detection probabilities. Previous entanglement and recycling techniques enhance postselection efficiency and signal-to-noise ratio (SNR) of weak measurement from distinct perspectives. Here, we incorporate a power recycling cavity into the entanglement-assisted weak measurement system. We obtain an improvement of both detection efficiency and Fisher information, and find that the improvement from entanglement and recycling occur in different dimensions. Furthermore, we analyze two types of errors, walk-off errors and readout errors. The conclusions suggest that entanglement exacerbates the walk-off effect caused by recycling, but this detriment can be balanced by proper parameter selection. In addition, power-recycling can complement entanglement in suppressing readout noise, thus enhancing the accuracy in the measurement results and recovering the lost Fisher information. This work delves deeper into the metrological advantages of weak measurement.