Out-of-Equilibrium Dynamics in the Two-Component Bose-Hubbard Model

TL;DR

This paper investigates the out-of-equilibrium behavior of a two-component Bose-Hubbard model, revealing richer dynamics and phase diagrams compared to single-component systems through a strong-coupling theoretical approach.

Contribution

It develops an effective theory and equations of motion for two-component bosons, extending understanding of their out-of-equilibrium dynamics and phase behavior.

Findings

Two-component bosons exhibit more complex out-of-equilibrium dynamics.

The phase diagram is richer due to additional degrees of freedom.

Derived equations describe superfluid order parameters during quenches.

Abstract

We study the out-of-equilibrium dynamics of the Bose-Hubbard model for two-component bosons using a strong-coupling approach within the closed-time-path formalism and develop an effective theory for the action of this problem. We obtain equations of motion for the superfluid order parameters of both boson species for both the superfluid and Mott-insulating phases and study these in the low-frequency, long-wavelength limit during a quantum quench for various initial conditions. We find that an additional degree of freedom for bosons leads to a richer phase diagram and out-of-equilibrium dynamics than the single-component situation.