Fragmented superfluid due to frustration of cold atoms in optical lattices

TL;DR

This paper investigates how frustration in a 1D optical lattice with internal atomic states leads to various quantum phases, including Mott insulator, superfluid breakdown, and fragmentation, revealing complex many-body phenomena.

Contribution

It introduces a novel model of a frustrated ladder system using internal atomic states in optical lattices, exploring phase transitions and fragmentation effects.

Findings

Frustration stabilizes the Mott insulator with ferromagnetic order.

Superfluidity breaks down under frustration, leading to fragmentation.

The system exhibits a macroscopically fragmented phase due to frustration.

Abstract

A one dimensional optical lattice is considered where a second dimension is encoded in the internal states of the atoms giving effective ladder systems. Frustration is introduced by an additional optical lattice that induces tunneling of superposed atomic states. The effects of frustration range from the stabilization of the Mott insulator phase with ferromagnetic order, to the breakdown of superfluidity and the formation of a macroscopically fragmented phase.