Quantum droplet of a two-component Bose gas in an optical lattice near the Mott insulator transition

TL;DR

This paper investigates the formation and control of quantum droplets in a two-component Bose-Hubbard system near the Mott insulator transition, revealing how trap potential manipulation induces self-bound states.

Contribution

It introduces a theoretical framework for creating and controlling quantum droplets in a two-component Bose gas using time-dependent Gutzwiller simulations and effective field theory.

Findings

Quantum droplets form in the superfluid region near the Mott insulator transition.

Droplet properties can be controlled via trap potential adjustments.

Effective Ginzburg-Landau theory captures static and dynamic droplet behavior.

Abstract

We theoretically study dynamical formation of a quantum droplet in a two-component Bose-Hubbard system with an external trap potential. Specifically, the superfluid in the central region surrounded by the Mott insulator with double filling forms a quantum droplet, which is self-bound thanks to the discontinuous nature of the quantum phase transition between the two phases. We show how to induce the characteristic behavior of the droplet through the control of the trap potential by using the time-dependent Gutzwiller simulations in a two-dimensional system. The static and dynamical properties of the droplet can be described qualitatively by the effective Ginzburg-Landau field theory with cubic-quintic nonlinearities, where the attractive cubic nonlinearlity emerges although all the bare interparticle interactions are repulsive.