QND measurements and state preparation in quantum gases by light detection

TL;DR

This paper explores how light scattering and photon detection in optical lattices enable QND measurements and the preparation of non-classical atomic states like squeezed and Schrödinger cat states, with potential for detailed quantum state analysis.

Contribution

It introduces a method for using light detection in optical cavities to perform QND measurements and generate complex atomic quantum states in ultracold gases.

Findings

Photon detection projects atomic states into squeezed and cat states.

Single quantum trajectories show modifications in atomic and light properties.

Final atomic states' quantum structure can be further analyzed.

Abstract

We consider light scattering from ultracold atoms trapped in an optical lattice into a cavity. The measurement of photons leaking out the cavity provides a quantum nondemolition (QND) access to various atomic variables. Depending on the chosen geometry the time resolved light detection projects the atomic quantum state to various atom-number squeezed and Schroedinger cat states. Modifications of the atomic and light properties at a single quantum trajectory are demonstrated. The quantum structure of final states can be revealed by further observations of the same sample.