Ground state properties of an asymmetric Hubbard model for unbalanced ultracold fermionic quantum gases |
| |
Authors: | T Gottwald P GJ van Dongen |
| |
Institution: | 1.KOMET 337, Institut für Physik, Johannes Gutenberg-Universit?t,Mainz,Germany |
| |
Abstract: | In order to describe unbalanced ultracold fermionic quantum gases on optical lattices in a harmonic trap, we investigate an
attractive (U < 0) asymmetric (t↑≠t↓) Hubbard model with a Zeeman-like magnetic field. In view of the model's spatial inhomogeneity, we focus in this paper on
the solution at Hartree-Fock level. The Hartree-Fock Hamiltonian is diagonalized with particular emphasis on superfluid phases.
For the special case of spin-independent hopping we analytically determine the number of solutions of the resulting self-consistency
equations and the nature of the possible ground states at weak coupling. We present the phase diagram of the homogeneous system
and numerical results for unbalanced Fermi-mixtures obtained within the local density approximation. In particular, we find
a fascinating shell structure, involving normal and superfluid phases. For the general case of spin-dependent hopping we calculate
the density of states and the possible superfluid phases in the ground state. In particular, we find a new magnetized superfluid
phase. |
| |
Keywords: | 03 75 Hh Static properties of condensates thermodynamical statistical and structural properties 39 25 +k Atom manipulation (scanning probe microscopy laser cooling etc ) 71 10 Fd Lattice fermion models (Hubbard model etc ) |
本文献已被 SpringerLink 等数据库收录! |