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TT: Fachverband Tiefe Temperaturen

TT 41: Matter at Low Temperature: Quantum Liquids, Bose-Einstein-Condensates, Ultra-cold Atoms

TT 41.16: Vortrag

Donnerstag, 26. März 2009, 18:15–18:30, HSZ 105

Quantum Dynamics of Optomechanical Systems — •Max Ludwig, Björn Kubala, and Florian Marquardt — Department of Physics, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität München,Theresienstr 37, D-80333 München, Germany

A generic optomechanical system consists of a driven optical cavity and a movable mirror attached to a cantilever. Recently, a new kind of optomechanical system has been realized by replacing the cantilever by a cloud of cold atoms located inside a cavity.

A common feature of optomechanical systems is the instability they can exhibit towards a regime where the mechanical oscillator settles into self-sustained oscillations. We analyze the quantum dynamics of these self-sustained oscillations using a master equation approach applied to the coupled system consisting of the cavity mode and the mechanical oscillation. When a suitable ``quantum parameter'' is sent to zero, these results converge towards the predictions of the classical theory of the instability. By contrast, for a large value of the quantum parameter the system is strongly influenced by quantum fluctuations.

Optomechanical systems involving the motion of ultracold atoms exhibit very large values of the quantum parameter and are hence expected to show substantial quantum effects. We discuss some prospects that open up for such kind of setups.