Mott transitions in ternary flavor mixtures of ultracold fermions on optical lattices

TL;DR

This paper investigates Mott transitions in SU(3) symmetric ultracold fermionic mixtures on optical lattices, revealing signatures observable at experimentally accessible temperatures through numerical solutions of the Hubbard model.

Contribution

It provides the first exact numerical analysis of Mott transitions in SU(3) fermionic mixtures, including spectral functions and the semi-compressible state near half filling.

Findings

Mott transitions occur near integer filling at low temperatures.

Signatures of Mott transitions persist at high temperatures.

Identification of a semi-compressible state near half filling.

Abstract

Ternary flavor mixtures of ultracold fermionic atoms in an optical lattice are studied in the case of equal, repulsive on-site interactions U>0. The corresponding SU(3) invariant Hubbard model is solved numerically exactly within dynamical mean-field theory using multigrid Hirsch-Fye quantum Monte Carlo simulations. We establish Mott transitions close to integer filling at low temperatures and show that the associated signatures in the compressibility and pair occupancy persist to high temperatures, i.e., should be accessible to experiments. In addition, we present spectral functions and discuss the properties of a ``semi-compressible'' state observed for large U near half filling.