Coherent matter waves emerging from Mott-insulators

TL;DR

This paper investigates how coherent matter waves form from a Mott insulator of strongly interacting bosons in one dimension, demonstrating persistence across various interaction strengths and exploring control methods.

Contribution

It extends understanding of matter wave emergence from Mott insulators to all interaction strengths and employs exact and numerical methods for analysis.

Findings

Coherent matter waves persist across all repulsive interactions in Mott insulators.

The non-equilibrium dynamics are exactly solvable for hard-core bosons.

Control methods for the emerging matter wave are discussed.

Abstract

We study the formation of (quasi-)coherent matter waves emerging from a Mott insulator for strongly interacting bosons on a one-dimensional lattice. It has been shown previously that a quasi-condensate emerges at momentum k=\pi/2a, where a is the lattice constant, in the limit of infinitely strong repulsion (hard-core bosons). Here we show that this phenomenon persists for all values of the repulsive interaction that lead to a Mott insulator at a commensurate filling. The non-equilibrium dynamics of hard-core bosons is treated exactly by means of a Jordan-Wigner transformation, and the generic case is studied using a time-dependent density matrix renormalization group technique. Different methods for controlling the emerging matter wave are discussed.