Two component Bose-Hubbard model with higher angular momentum states

TL;DR

This paper explores a two-component Bose-Hubbard model with higher angular momentum states in ultracold Chromium atoms, revealing how dipolar interactions induce spin flips and orbital angular momentum, leading to diverse stable phases.

Contribution

It introduces a novel two-component Bose-Hubbard model incorporating higher angular momentum states and analyzes the resulting phase diagram under dipolar interactions.

Findings

Resonant dipolar interactions enable spin flips and orbital angular momentum creation.

Multiple stable phases are identified in the phase diagram.

Angular momentum conservation links spin changes to orbital excitations.

Abstract

We study a Bose-Hubbard Hamiltonian of ultracold two component gas of spinor Chromium atoms. Dipolar interactions of magnetic moments while tuned resonantly by ultralow magnetic field can lead to spin flipping. Due to approximate axial symmetry of individual lattice site, total angular momentum is conserved. Therefore, all changes of the spin are accompanied by the appearance of the angular orbital momentum. This way excited Wannier states with non vanishing angular orbital momentum can be created. Resonant dipolar coupling of the two component Bose gas introduces additional degree of control of the system, and leads to a variety of different stable phases. The phase diagram for small number of particles is discussed.