Tomonaga-Luttinger liquid theory for one-dimensional attractive Fermi gases
This work develops a universal Tomonaga-Luttinger liquid (TLL) theory to describe the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in 1D attractive Fermi gases under weak and strong binding. The study reveals a two-component TLL structure: spin and charge coupling when binding is weak, and charge separation when binding is strong. This provides a rigorous framework to understand complex pairing states.