Dimensional crossover on multileg attractive- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>U</mml:mi></mml:math> 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 up to $W=5$ varying perpendicular geometries, characterizing quasi-one-dimensional regime dimensional crossover. unveil multicritical point marking onset partial polarization in those diagrams, candidate finite-momentum pairing. compare our findings with recent experimental theoretical studies gases.