Phase diagrams of polarized ultra-cold gases on attractive-U Hubbard ladders

TL;DR

This paper explores the phase diagrams of polarized two-component Fermi gases on attractive-U Hubbard ladders with one to three legs, revealing how multi-leg ladders exhibit features akin to the 1D-to-3D crossover in ultracold gases.

Contribution

It constructs the grand canonical phase diagram for polarized gases on multi-leg Hubbard ladders, highlighting differences from single-chain models and connecting to experimental crossovers.

Findings

Multi-leg ladders show distinct phase structures from single chains.

Phase diagrams reflect the 1D-to-3D crossover in ultracold gases.

Single chain is a special case of multi-leg ladder models.

Abstract

We consider a quasi-one-dimensional model of a two-component Fermi gas at zero temperature on one, two and three-leg attractive-U Hubbard ladders. We construct the grand canonical phase diagram of a two-component spin-polarized gas. We find that the structure of the phase diagram of the attractive-U Hubbard model for two and three leg ladders significantly differs q from the structure of the phase diagram of a single chain. We argue that the single chain model is a special case, and that multichain ladders display qualitative features of the 1D-to-3D crossover, observed in experiments with trapped ultracold gases.