Tunable anisotropic magnetism in trapped two-component Bose gases

TL;DR

This paper theoretically investigates magnetic phases in two-component Bose gases in optical lattices, revealing the persistence of XY-ferromagnetic and anti-ferromagnetic order in trapped systems using Bosonic Dynamical Mean-Field Theory.

Contribution

It provides the first detailed phase diagram of magnetic order in the two-component Bose-Hubbard model in 3D, including effects of trapping.

Findings

Magnetic phases include XY-ferromagnetic and anti-ferromagnetic states.

Magnetic order persists in trapped systems.

Phase diagram mapped using Bosonic Dynamical Mean-Field Theory.

Abstract

We theoretically address magnetic ordering at zero and finite temperature in both homogeneous and trapped Bose-Bose mixtures in optical lattices. By using Bosonic Dynamical Mean-Field Theory, we obtain the phase diagram of the homogeneous two-component Bose-Hubbard model in a three-dimensional (3D) cubic lattice, which features competing magnetic order of XY-ferromagnetic and anti-ferromagnetic type in addition to the Mott and superfluid states. We show that these magnetic phases persist also in the presence of a harmonic trap.