Absence of the Twisted Superfluid State in a mean field model of bosons on a Honeycomb Lattice

TL;DR

This paper investigates the stability of a Bose-Einstein Condensate in a honeycomb lattice and finds no evidence of the predicted Twisted Superfluid state within a mean field framework, suggesting the need for beyond-mean-field theories.

Contribution

The study provides a comprehensive mean field analysis showing the absence of the Twisted Superfluid phase, challenging previous experimental interpretations.

Findings

No Twisted Superfluid phase found in mean field model

Results suggest non-mean field effects may be necessary to explain experiments

Highlights limitations of mean field approaches for this system

Abstract

Motivated by recent observations (P. Soltan-Panahi {\it et al.}, Nature Physics {\bf 8}, 71-75 (2012)), we study the stability of a Bose-Einstein Condensate within a spin-dependent honeycomb lattice towards forming a "Twisted Superfluid" state. Our exhaustive numerical search fails to find this phase, pointing to possible non-mean field physics.