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Q: Quantenoptik
Q 321: Bose-Einstein Kondensation II
Q 321.8: Talk
Wednesday, March 6, 2002, 18:15–18:30, HS 22/B01
Quantum field theory of dilute homogeneous Bose-Fermi mixtures at zero temperature: general formalism and beyond mean-field corrections — •Alexander Albus1, Simon Gardiner1,2, Fabrizio Illuminati3,4 und Martin Wilkens1 — 1Institut für Physik, Universität Potsdam, D–14469 Potsdam, Germany — 2Institut für Theoretische Physik, Universität Hannover, D–30167 Hannover, Germany — 3Dipartimento di Fisica, Università degli Studi di Salerno, I–84081 Baronissi (SA), Italy — 4Istituto Nazionale di Fisica della Materia (INFM), Unità di Salerno, Baronissi (SA), Italy
After the achivement of Bose-Einstein condensation and recent experimental activity on quantum degenerate Fermi gases, there is also an increasing experimental and theoretical interest in quantum degenerate mixtures of Boson and Fermion gases. Existing theories on Boson-Fermion mixtures adopt mean-field approximations. In order to take into account beyond mean field effects, we construct a formal scheme for carrying out systematic perturbation theory in terms of single particle Green’s functions. Using this approach we find a new term in the ground state energy of a weakly-interacting homogeneous mixture of Bosons and spin-polarized Fermions at zero temperature. We discuss the relevance of this new term, how it can be incorporated into existing theories of Boson-Fermion mixtures, and its importance in various parameter regimes, in particular considering mixtures of 6Li and 7Li and of 3He and 4He.