Heterodyne non-demolition measurements on cold atomic samples: towards the preparation of non-classical states for atom interferometry

TL;DR

This paper demonstrates a heterodyne quantum non-demolition measurement technique on cold atomic samples within a high finesse ring cavity, enabling non-destructive monitoring of atomic states for potential non-classical state preparation in atom interferometry.

Contribution

It introduces a heterodyne QND detection method with shot-noise limited sensitivity and GHz bandwidth, advancing non-destructive atomic state measurements.

Findings

Achieved shot-noise limited heterodyne detection

Successfully monitored atomic state evolution non-destructively

Demonstrated potential for preparing non-classical states

Abstract

We report on a novel experiment to generate non-classical atomic states via quantum non-demolition (QND) measurements on cold atomic samples prepared in a high finesse ring cavity. The heterodyne technique developed for the QND detection exhibits an optical shot-noise limited behavior for local oscillator optical power of a few hundred \muW, and a detection bandwidth of several GHz. This detection tool is used in single pass to follow non destructively the internal state evolution of an atomic sample when subjected to Rabi oscillations or a spin-echo interferometric sequence.