Experimental quantum-enhanced estimation of a lossy phase shift

TL;DR

This paper demonstrates experimentally that specially engineered quantum states can surpass traditional and N00N states in phase estimation precision even with losses, advancing quantum metrology.

Contribution

It introduces engineered quantum states that outperform standard and N00N states in lossy phase estimation, showing practical quantum advantage.

Findings

Engineered quantum states outperform N00N states under loss.

Quantum states exceed shot noise limit in phase estimation.

Experimental validation of quantum advantage in lossy conditions.

Abstract

When standard light sources are employed, the precision of the phase determination is limited by the shot noise. Quantum entanglement provides means to exceed this limit with the celebrated example of N00N states that saturate the ultimate Heisenberg limit on precision, but at the same time are extremely fragile to losses. In contrast, we provide experimental evidence that appropriately engineered quantum states outperform both standard and N00N states in the precision of phase estimation when losses are present.