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A: Fachverband Atomphysik
A 18: Ultracold atoms II (jointly with Q)
A 18.4: Vortrag
Donnerstag, 13. März 2008, 09:15–09:30, 2F
Quantum State Engineering via Dissipation — •H.P. Büchler1, S. Diehl2, A. Kantian2, B. Kraus3, A. Micheli2, and P. Zoller2,3 — 1Institut für Theoretische Physik, Universität Stuttgart — 2Institut für Quantenoptik und Quanteninformation, Universität Innsbruck — 3Insitut für Theoretische Physik, Universität Innsbruck
An open quantum system, whose time evolution is governed by a master equation, can be driven in steady state into a given pure quantum state by an appropriate design of the system-reservoir coupling. This points out a route towards preparing many body states and non-equilibrium quantum phases by quantum reservoir engineering. Here we discuss in detail the example of a driven dissipative Bose Einstein Condensate (BEC), where atoms in an optical lattice are coupled to a bath of Bogoliubov excitations via the atomic current representing local dissipation. In the absence of interactions the lattice gas is driven into a pure state with long range order. Weak interactions lead to a weakly mixed state, which in 3D can be understood as a depletion of the condensate, and in 1D and 2D exhibits properties reminiscent of a Luttinger liquid or a Kosterlitz-Thouless critical phase at finite temperature, with the role of the ``finite temperature'' played by the interactions.