States of fermionic atoms in an optical superlattice across a Feshbach resonance

TL;DR

This paper explores the behavior of fermionic atoms in an optical superlattice near a Feshbach resonance, revealing quantum phase transitions through level crossings and superpositions of atomic states.

Contribution

It introduces a model for fermionic atoms in a superlattice with limited interactions, highlighting the role of superpositions and symmetry changes across a Feshbach resonance.

Findings

Level crossing indicates potential quantum phase transition.

States are superpositions of resonating valence bonds and dressed molecules.

Interaction is confined to a small number of lattice sites.

Abstract

We investigate states of fermionic atoms across a broad Feshbach resonance in an optical superlattice which allows interaction only among a small number of lattice sites. The states are in general described by superpositions of atomic resonating valence bonds and dressed molecules. As one scans the magnetic field, level crossing is found between states with different symmetry properties, which may correspond to a quantum phase transition in the many-body case.