# Vortex lattice melting in a boson-ladder in artificial gauge field

## TL;DR

This paper investigates how interleg attractive interactions in a boson ladder under an artificial gauge field lead to a sequence of phase transitions, including vortex melting, characterized by dislocations, in a cold atom experimental setup.

## Contribution

It reveals a novel sequence of phase transitions involving Ising and disorder points, and predicts observable signatures in cold atom experiments.

## Key findings

- Vortex state can be melted by dislocations due to attractive interactions.
- Sequence of phase transitions includes Ising transition and disorder point.
- Predicted observable effects include changes in spin current and structure factor.

## Abstract

We consider a two-leg boson ladder in an artificial U(1) gauge field and show that, in the presence of interleg attractive interaction, the flux induced Vortex state can be melted by dislocations. For increasing flux, instead of the Meissner to Vortex transition in the commensurate-incommensurate universality class, first an Ising transition from the Meissner state to a charge density wave takes place, then, at higher flux, the melted Vortex phase is established via a disorder point where incommensuration develops in the rung current correlation function and in momentum distribution.Finally, the quasi-long range ordered Vortex phase is recovered for sufficiently small interaction. Our predictions for the observables, such as the spin current and the static structure factor, could be tested in current experiments with cold atoms in bosonic ladders.