Phase separation in a two species Bose mixture

TL;DR

This paper investigates the quantum phase diagram of a two-species Bose mixture in a 1D optical lattice, revealing superfluid, Mott insulator, and novel phase separation phases using DMRG methods.

Contribution

It introduces the observation of a new phase separation phenomenon in two-species Bose mixtures, classified into PS-SF and PS-MI, across various fillings and interaction strengths.

Findings

Phase separation occurs when inter-species interaction exceeds intra-species interactions.

Identified phases include superfluid, Mott insulator, and two types of phase-separated states.

Phase separation is present across all considered fillings with slight inter-species interaction dominance.

Abstract

We study the ground state quantum phase diagram for a two species Bose mixture in a one-dimensional optical lattice using the finite size density matrix renormalization group(FSDMRG) method. We discuss our results for different combinations of inter and intra species interaction strengths with commensurate and incommensurate fillings of the bosons. The phases we have obtained are superfluid, Mott insulator and a novel phase separation, where different species reside in spatially separate regions. The spatially separated phase is further classified into phase separated superfluid(PS-SF) and Mott insulator(PS-MI). The phase separation appears for all the fillings we have considered, whenever the inter-species interaction is slightly larger than the intra-species interactions.