Superfluid to Mott-insulator transition in Bose-Hubbard models.
We study the superfluid-insulator transition in Bose-Hubbard models in one-, two-, and three-dimensional cubic lattices by means of a recently proposed variational wave function. In one dimension, the variational results agree with the expected Berezinskii-Kosterlitz-Thouless scenario of the interaction-driven Mott transition. In two and three dimensions, we find evidence that, across the transition, most of the spectral weight is concentrated at high energies, suggestive of preformed Mott-Hubbard sidebands. This result is compatible with the experimental data by Stoferle et al. [Phys. Rev. Lett. 92, 130403 (2004)].
Capello
Manuela
M
Laboratoire de Physique Théorique, Université Paul Sabatier, CNRS, 31400 Toulouse, France.
Becca
Federico
F
Fabrizio
Michele
M
Sorella
Sandro
S