Variational Approach for the Bose-Hubbard Model

M. Melé-Messeguer, Bruno Juliá-Díaz, A. Polls

Benjamin Bogner, Clément De Daniloff, Heiko Rieger

Jay D. Mancini, Vassilios Fessatidis, S.P. Bowen +1 more

Jan Major, Mateusz Łącki, Jakub Zakrzewski

For strongly interacting bosons in optical lattices, the standard description using the Bose-Hubbard model becomes questionable. The role of excited bands becomes important. In such a situation, we compare results of simulations using the multiband Bose-Hubbard model with a recent proposition based on a time-dependent variational approach. It is shown that the latter, in its original formulation, uses a too small variational space, often leading to spurious effects. Possible expansion of the variational approach is discussed.

Deshui Yu, Jingbiao Chen

The phase diagram of the one-dimensional Bose–Hubbard model describing interacting bosons in optical lattice is investigated with the variational approach. This method can also be generalized to the two-dimensional case.

Balázs Hetényi, Hans Gerd Evertz, Xiancong Lu