Interaction-induced localization of fermionic mobile impurities in a Larkin-Ovchinnikov superfluid

TL;DR

This paper explores how fermionic impurities in a 2D LO superfluid become localized and form pairs under strong interactions, leading to a transition from checkerboard to stripe phases, with implications for experimental observation.

Contribution

It introduces a theoretical model explaining impurity localization and phase transitions in a 2D LO superfluid, highlighting the role of impurity interactions.

Findings

Impurity atoms become localized and form pairs with strong interactions.

Finite impurity concentration induces a phase transition from checkerboard to stripe LO state.

Effective model reveals the mechanism behind self-localization and phase transition.

Abstract

We theoretically investigate the interplay between the fermionic mobile impurity atoms and a Larkin-Ovchinnikov (LO) superfluid in a two dimensional optical lattice. We find that the impurity atoms get localized and can form pairs when the interaction between the impurity atoms and the LO superfluid is strong enough. These features are due to the phenomena of self-localization whose underlying mechanism is revealed by an effective model. The impurity atoms with finite concentrations can drive the transition from a two-dimensional-checkerboard-like LO state to a quasi-one-dimensional-stripe-like one. Experimental preparations to observe these features are also discussed.