Near Heisenberg limited atomic clocks in the presence of decoherence

TL;DR

This paper introduces an adaptive measurement protocol that enables atomic clocks with entangled atoms to approach Heisenberg-limited stability even with realistic decoherence, advancing quantum metrology.

Contribution

The authors propose a novel adaptive measurement protocol that mitigates decoherence effects, allowing near Heisenberg-limited atomic clock stability with entangled atoms.

Findings

Achieves near Heisenberg-limited stability despite decoherence

Demonstrates robustness of the protocol against realistic noise

Enhances quantum metrology potential with entangled states

Abstract

The ultimate stability of atomic clocks is limited by the quantum noise of the atoms. To reduce this noise it has been suggested to use entangled atomic ensembles with reduced atomic noise. Potentially this can push the stability all the way to the limit allowed by the Heisenberg uncertainty relation, which is denoted the Heisenberg limit. In practice, however, entangled states are often more prone to decoherence, which may prevent reaching this performance. Here we present an adaptive measurement protocol that in the presence of a realistic source of decoherence enables us to get near Heisenberg limited stability of atomic clocks using entangled atoms. The protocol may thus realize the full potential of entanglement for quantum metrology despite the detrimental influence of decoherence.