Multi-orbital and density-induced tunneling of boson in optical lattices
Hao Lee (doctorant au LPTMS)
Article de Dirk-Soren Luhmann, Ole Jurgensen and Klaus Sengstock, New Journal of Physics 14 ( 2012) 033021
We show that multi-orbital and density-induced tunneling have a significant impact on the phase diagram of bosonic atoms in opticallattices. Off-site interactions lead to density-induced hopping, the so-called bond-charge interactions, which can be identified with an effective tunneling potential 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.We derive an extended occupation-dependent Hubbard model with multiorbitallyrenormalized processes and compute the corresponding phase diagram.It substantially deviates from the single-band Bose–Hubbard model andpredicts strong changes of the superfluid-to-Mott-insulator transition. In general,the presented beyond-Hubbard physics plays an essential role in bosoniclattice systems and has an observable influence on experiments with tunableinteractions.