Multiband-Driven Superfluid-Insulator Transition of Fermionic Atoms in Optical Lattices: A Dynamical Mean-Field-Theory Study

TL;DR

This study uses two-site dynamical mean-field theory to explore how multiband effects induce superfluid-insulator transitions in fermionic atoms within optical lattices, revealing significant quasiparticle weight reduction near the transition.

Contribution

It demonstrates that multiband effects drive the Mott transition in fermionic optical lattices, providing detailed phase diagrams and insights into quasiparticle behavior.

Findings

Mott transition driven by multiband effects

Quasiparticle weight decreases near transition

Phase diagram at half filling obtained

Abstract

The superfluid-insulator transitions of the fermionic atoms in optical lattices are investigated by the two-site dynamical mean-field theory. It is shown that the Mott transition occurs as a result of the multiband effects. The quasiparticle weight in the superfluid state decreases significantly, as the system approaches the Mott transition point. By changing the interaction and the orbital splitting, we obtain the phase diagram at half filling. The numerical results are discussed in comparison with the effective boson model.