Improving cold-atom sensors with quantum entanglement: Prospects and challenges

TL;DR

This paper reviews the potential of quantum entanglement to enhance cold-atom sensors, discussing current capabilities, benefits, challenges, and methods for generating useful entanglement to improve measurement precision.

Contribution

It provides a comprehensive overview of how entanglement could improve cold-atom sensors and evaluates the feasibility of implementing quantum-enhanced sensing in practical devices.

Findings

Entanglement can potentially surpass shot-noise limits in cold-atom sensors.

Current methods for generating entanglement have varying strengths and limitations.

Realizing quantum-enhanced cold-atom sensing faces significant technical challenges.

Abstract

Quantum entanglement has been generated and verified in cold-atom experiments and used to make atom-interferometric measurements below the shot-noise limit. However, current state-of-the-art cold-atom devices exploit separable (i.e. unentangled) atomic states. This Perspective piece asks the question: can entanglement usefully improve cold-atom sensors, in the sense that it gives new sensing capabilities unachievable with current state-of-the-art devices? We briefly review the state-of-the-art in precision cold-atom sensing, focussing on clocks and inertial sensors, identifying the potential benefits entanglement could bring to these devices, and the challenges that need to be overcome to realize these benefits. We survey demonstrated methods of generating metrologically-useful entanglement in cold-atom systems, note their relative strengths and weaknesses, and assess their prospects for near-to-medium term quantum-enhanced cold-atom sensing.