Quantum measurement backaction from a BEC coupled to a mechanical oscillator

TL;DR

This paper theoretically explores a hybrid quantum system where a Bose-Einstein condensate coupled to a mechanical membrane allows indirect measurement of membrane motion and the potential generation of non-classical states through measurement backaction.

Contribution

It introduces a novel hybrid system combining a BEC and a mechanical membrane with magnetic coupling, analyzing measurement backaction and state generation possibilities.

Findings

Measurement backaction significantly affects membrane dynamics.

Repeated measurements can potentially reveal quantum backaction.

The system can generate non-classical Schrödinger cat states.

Abstract

We study theoretically the dynamics of a a hybrid optomechanical system consisting of a macroscopic mechanical membrane magnetically coupled to a spinor Bose-Einstein condensate via a nanomagnet attached at the membrane center. We demonstrate that this coupling permits us to monitor indirectly the center-of-mass position of the membrane via measurements of the spin of the condensed atoms. These measurements normally induce a significant backaction on the membrane motion, which we quantify for the cases of thermal and coherent initial states of the membrane. We discuss the possibility of measuring that quantum backaction via repeated measurements. We also investigate the potential to generate non-classical states of the membrane, in particular Schrodinger cat states, via such repeated measurements.