The one-dimensional extended Bose-Hubbard model

David L. Feder, Farokh Mivehvar

Laura Urba, Emil Lundh, Anders Rosengren

The extended Bose–Hubbard model in a quadratic trap potential is studied using a finite-size density-matrix renormalization group method (DMRG). We compute the boson density profiles, the local compressibility and the hopping correlation functions. We observe the phase separation induced by the trap in all the quantities studied and conclude that the local density approximation is valid in the extended Bose–Hubbard model. From the plateaus obtained in the local compressibility it was possible to obtain the phase diagram of the homogeneous system which is in agreement with previous results.

P. Gluck

Florian Gebhard

Min-Chul Cha, Jong-Geun Shin

The critical properties of the one-dimensional hard-core extended Bose-Hubbard model at half-filling, involving both XY- and the Ising-symmetry breaking, are studied on a lattice up to 32 sites via the Lanczos method. The finite-size scaling behaviors as approached from either the insulator or the superfluid side are consistent with the presence of an essential singularity, suggesting that the transition has Kosterllitz-Thouless (KT)-type universal properties.

M. S. Laad, Dipan K. Ghosh