Hamburg 2009 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 24: Ultra-Cold Atoms, Ions and BEC II (with Q)

A 24.2: Vortrag

Donnerstag, 5. März 2009, 11:00–11:15, VMP 6 HS-C

Dissipative processes of a trapped atom approaching conditions of electromagnetically induced transparency — •Maryam Roghani, Heinz-Peter Breuer, and Hanspeter Helm — University of Freiburg, Hermann-Herderstr. 3,D-79104 Freiburg, Germany

We study a three-level atom trapped in a one-dimensional quantum mechanical harmonic oscillator, interacting with two counter-propagating laser beams. Atom-light interaction leads to an entangled state of electronic and vibrational degrees of freedom. We show that by prudent choice of experimental parameters the atom approaches EIT-like (Electromagnetically Induced Transparency) conditions as it is cooled down to the lowest level of the trap [1], even beyond the Lamb-Dicke limit. Solving numerically the master equation gives us the opportunity to derive from the time-dependent density matrix elements the evolution of transparency and entanglement, together with the force and dissipation terms which are active in the removal of translational energy from the trapped atom. This scheme may find application in the purely optical preparation of Bose-Einstein condensates without evaporative cooling and also in the laser-cooling of macroscopic objects of crystalline matter. [1]. Trapped-Atom Cooling Beyond The Lamb-Dicke Limit Using Electromagnetically-Induced Transparency, M. Roghani and H. Helm , Physical Review A 77, 043418 (2008).