[Prof. Yoon-Ho Kim] Heisenberg-Limited Metrology via Weak-Value Amplif…

Caption : The Heisenberg limit can be reached with repetitive interaction with interaction parameters 

[Prof. Yoon-Ho Kim]Heisenberg-Limited Metrology via Weak-Value Amplification without Using Entangled Resources 

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.