Achieving ground state and enhancing optomechanical entanglement by recovering information


For cavity-assisted optomechanical cooling experiments, in order to achieve the quantum ground state of the mechanical oscillator, the cavity bandwidth needs to be smaller than the mechanical frequency. In the literature, this is the so-called resolved-sideband or good-cavity limit, and this is based on an understanding of optomechanical dynamics. We provide a different but physically equivalent explanation of such a limit: that is, information loss due to finite cavity bandwidth. With an optimal feedback control to recover the information in the cavity output, we can surpass the resolved-sideband limit and achieve the quantum ground state. In addition, recovering this information can also significantly enhance the entanglement between the cavity mode and the mechanical oscillator. Especially when the environmental temperature is high, such optomechanical entanglement will either exist or vanish critically depending on whether information is recovered or not. This provides a vivid example of a quantum eraser in the optomechanical system. 5 Author to whom any correspondence should be addressed. New Journal of Physics 12 (2010) 083032 1367-2630/10/083032+19$30.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

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@inproceedings{Miao2010AchievingGS, title={Achieving ground state and enhancing optomechanical entanglement by recovering information}, author={Haixing Miao and Stefan L. Danilishin and Helge M{\"{u}ller-Ebhardt and Yanbei Chen}, year={2010} }