Quasi-Long-Range-Order in Mott State of Bose–Fermi Mixtures on One-Dimensional Optical Lattice

Abstract

We numerically studied internal structure of Mott insulating state of Bose–Fermi mixture systems on a one-dimensional optical lattice by using quantum Monte Carlo simulations. We looked for Mott state carefully adjusting various parameters to prevent phase separation. From the calculation of density–density correlation functions we found a quasi long-range order in the particle distribution in the Mott state. The order was strongly dependent of the ratio of the number of the bosons to that of the fermions. For example, the bosons and the fermions showed a tendency of aligning alternately when equal number of the bosons and fermions are introduced in the system. The observation of the quasi long-range order in the one-dimensional system indicates the presence of true long-range order in Bose–Fermi mixtures on a three-dimensional optical lattice.