Düsseldorf 2007 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 21: Quanteneffekte (Offene und Wenigteilchensysteme)
Q 21.4: Talk
Tuesday, March 20, 2007, 11:15–11:30, 5E
Quantum Efficiency of Atomic Extraction from an Ultracold Atomic Reservoir — Bernd Mohring1, Giovanna Morigi2, •Eric Lutz3, and Wolfgang P. Schleich1 — 1Institut für Quantenphysik, Universität Ulm, 89069 Ulm, Germany — 2Grup d’Optica, Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain — 3Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
We study the efficiency of coherent extraction of cold atoms from a reservoir, a Bose-Einstein condensate (BEC), as in the setup proposed in [1]. Here, the atoms are coherently transferred from a BEC to the ground state of a steep microtrap in the collisional blockade regime by means of a laser. In this setup, the condensate excitations constitute a source of quantum noise, which is non-Markovian in the parameter regime of interest. To describe the dynamics for this realization of quantum tweezers we derive a master equation. Using the time-convolutionless projection operator technique [2] we obtain a closed equation for the reduced system — ground state of the condensate and ground state of the microtrap — which allows us to investigate the quantum efficiency of extraction.
[1] B. Mohring et al., Phys. Rev. A 71, 053601 (2005)
[2] H.-P. Breuer et al., Ann. Phys. (NY) 291, 36 (2001)