Quantum-measurement backaction from a Bose-Einstein condensate coupled to a mechanical oscillator
We study theoretically the dynamics of 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 this quantum backaction via repeated measurements. We also investigate the potential to generate nonclassical states of the membrane, in particular Schrödinger-cat states, via such repeated measurements.
Additional Information© 2011 American Physical Society. Received 9 May 2011; published 25 August 2011. We thank David Brown for his help during the initial stages of these calculations. This work was supported by the DARPA QuASAR program through a Grant from AFOSR and the DARPA-ORCHID program through a Grant from ARO, the US Army Research Office, and the NSF. M.V. acknowledges support from the Alfred P. Sloan Foundation. MET is supported by TUBITAK (the Scientific and Technological Research Council of Turkey).
Published - Steinke2011p15701Phys_Rev_A.pdf