Heisenberg-limited metrology via weak-value amplification without using entangled resources

TL;DR

This paper introduces a new weak-value amplification scheme that achieves Heisenberg-limited precision without entanglement, using iterative interactions to enhance measurement sensitivity in quantum metrology.

Contribution

It demonstrates a novel iterative interaction-based WVA method that attains Heisenberg-limit precision without entangled resources, simplifying experimental requirements.

Findings

Achieves Heisenberg-limited scaling without entanglement

Uses iterative interactions to enhance measurement precision

Provides a practical approach for quantum metrology

Abstract

Weak-value amplification (WVA) provides a way for amplified detection of a tiny physical signal at the expense of a lower detection probability. Despite this trade-off, due to its robustness against certain types of noise, WVA has advantages over conventional measurements in precision metrology. Moreover, it has been shown that WVA-based metrology can reach the Heisenberg-limit using entangled resources, but preparing macroscopic entangled resources remains challenging. Here we demonstrate a novel WVA scheme based on iterative interactions, achieving the Heisenberg-limited precision scaling without resorting to entanglement. This indicates that the perceived advantages of the entanglement-assisted WVA are in fact due to iterative interactions between each particle of an entangled system and a meter, rather than coming from the entanglement itself. Our work opens a practical pathway for achieving the Heisenberg-limited WVA without using fragile and experimentally-demanding entangled resources.