Dimensional crossover on multileg attractive-U Hubbard ladders

We study the ground-state properties of a polarized two-component Fermi gas on multileg attractive -U Hubbard ladders. Using exact diagonalization and density-matrix renormalization-group-method simulations, we construct grand-canonical phase diagrams for ladder widths of up to W = 5 and varying perpendicular geome-tries, characterizing the quasi-one-dimensional regime of the dimensional crossover. We unveil a multicritical point marking the onset of partial polarization in those phase diagrams, a candidate regime of finite-momentum pairing. We compare our findings with recent experimental and theoretical studies of quasi-one-dimensional polarized Fermi gases.

Automated summary

We study the ground-state properties of a polarized two-component Fermi gas on attractive -U Hubbard ladders with multiple legs. By exact diagonalization and density-matrix renormalization-group-method simulations, we construct grand-canonical phase diagrams for ladder widths up to W = 5 and varying perpendicular geometries, characterizing the quasi-one-dimensional regime of the dimensional crossover. We discover a multicritical point marking the onset of partial polarization in those phase diagrams, which suggests a regime of finite-momentum pairing. We compare our findings with recent experimental and theoretical studies of quasi-one-dimensional polarized Fermi gases.