Quantum-Enhanced Sensing Based on Time Reversal of Nonlinear Dynamics

TL;DR

This paper demonstrates a quantum-enhanced sensing method using time-reversal of nonlinear dynamics in Bose-Einstein condensates, enabling improved measurements with entangled states and controlled nonlinear transformations.

Contribution

It introduces a novel nonlinear detection scheme utilizing time-reversal dynamics and constructs an active atom SU(1,1) interferometer for quantum-enhanced measurements.

Findings

Successful experimental demonstration of nonlinear detection scheme

Entangled states generated and read out via controlled phase imprinting

Enhanced measurement precision using mean atom number detection

Abstract

We experimentally demonstrate a nonlinear detection scheme exploiting time-reversal dynamics that disentangles continuous variable entangled states for feasible readout. Spin-exchange dynamics of Bose-Einstein condensates is used as the nonlinear mechanism which not only generates entangled states but can also be time reversed by controlled phase imprinting. For demonstration of a quantum-enhanced measurement we construct an active atom SU(1,1) interferometer, where entangled state preparation and nonlinear readout both consist of parametric amplification. This scheme is capable of exhausting the quantum resource by detecting solely mean atom numbers. Controlled nonlinear transformations widen the spectrum of useful entangled states for applied quantum technologies.