Quantum Physics
Multi-orbital and density-induced tunneling in optical lattices
13 March 2012
Photo: AG Sengstock
We show that multi-orbital and density-induced tunneling have significant impact on the phase diagram of bosonic atoms and Bose-Fermi mixtures in optical lattices. Off-site interactions lead to density-induced hopping, so-called bond-charge interactions and can reach the same order of magnitude as conventional tunneling. In addition, interaction-induced higher-band processes also give rise to strongly modified tunneling, on-site, and bond-charge interactions. The derived phase diagrams deviate substantially from the single-band Bose-Hubbard predictions indicating strong changes of the SF-MI transition point.