Phase separation in the Hubbard model

Abstract

We study the behavior of the mean number of particles 〈n〉 (density) as a function of the chemical potential μ in the two-dimensional Hubbard model, using a quantum Monte Carlo method. Working at U/t=10, 4, and -4 on lattices with 4×4, 6×6, and 8×8 sites, we do not find evidence of phase separation.