Decoherence of Bloch oscillations of cold Fermi atoms in optical lattices

Alexey Ponomarev

Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden, Germany

The phenomenon of Bloch oscillations (BOs) is usually discussed in the context of electrons in semiconductor superlattices. Recently, BOs were observed with cold atoms loaded into an optical lattice. While most of the experimental and theoretical work on atomic BOs deals with spinless atoms, in this present work we address BOs of Fermi atoms. Our analysis is performed in terms of the 1D Hubbard model, where the relevant parameters are the filling factors (average number of atoms per lattice site) for spin-up and spin-down atoms, the magnitude of the static force, the tunneling matrix element and the interaction parameter which describes the on-site interaction between the spin-up and spin-down atoms. We observe a transition from fully coherent to decaying BOs, under changes of the single component filling factors, which tune the effective particle-particle interaction.