arXiv:0805.1812 · Journal of Physics B Atomic Molecular and Optical Physics
Two-particle states in the Hubbard model
Manuel Valiente, David Petrosyan
Abstract
We consider a pair of bosonic particles in a one-dimensional tight-binding periodic potential described by the Hubbard model with an attractive or repulsive on-site interaction. We derive explicit analytic expressions for the two-particle states, which can be classified as (i) scattering states of asymptotically free particles and (ii) interaction-bound dimer states. Our results provide a very transparent framework to understand the properties of interacting pairs of particles in a lattice.