Stripe-ordered superfluid and supersolid phases in attractive Hofstadter-Hubbard model

TL;DR

This paper investigates how the Hofstadter butterfly spectrum influences superfluidity in an attractive Hubbard model, revealing stripe-ordered superfluid and supersolid phases due to symmetry breaking, with implications for cold atom experiments.

Contribution

It introduces the first detailed phase diagram showing stripe-ordered superfluid and supersolid phases in the attractive Hofstadter-Hubbard model using Bogoliubov-de Gennes formalism.

Findings

Stripe-ordered superfluid phases are stabilized in large parameter regions.

Stripe-ordered supersolid phases coexist with superfluidity.

Trapping potentials affect the observability of these phases.

Abstract

We use microscopic Bogoliubov-de Gennes formalism to explore the ground-state phase diagram of the single-band attractive Hofstadter-Hubbard model on a square lattice. We show that the interplay between the Hofstadter butterfly and superfluidity breaks spatial symmetry, and gives rise to stripe-ordered superfluid and supersolid phases in large parameter spaces. We also discuss the effects of a trapping potential and comment on the viability of observing stripe-ordered phases with cold Fermi gases.