Quantum phase transitions and the degree of nonidentity in the system with two different species of vector bosons

TL;DR

This paper investigates how the degree of nonidentity between two species of vector bosons in an optical lattice influences quantum phase transitions, revealing qualitatively different phase diagrams as nonidentity increases.

Contribution

It introduces the concept of atomic nonidentity into the study of quantum phase transitions in multi-species bosonic systems and maps out the resulting phase diagram evolution.

Findings

Quantum phase transitions increase with atomic nonidentity.

Phase diagrams change from Miró-like to Malewicz-like images as nonidentity grows.

Strongly distinct atoms lead to qualitatively different phase behavior.

Abstract

We address the system with two species of vector bosons in an optical lattice. In addition to the the standard parameters characterizing such a system, we are dealing here with the "degree of atomic nonidentity", manifesting itself in the difference of tunneling amplitudes and on-site Coulomb interactions. We obtain a cascade of quantum phase transitions occurring with the increase in the degree of atomic nonidentity. In particular, we show that the phase diagram for strongly distinct atoms is qualitatively different from that for (nearly) identical atoms considered earlier. The resulting phase diagrams evolve from the images similar to the "J. Mir\'o-like paintings" to "K. Malewicz-like" ones.