Dynamical Mean Field Theory of the Bilayer Hubbard Model with Inchworm Monte Carlo

Abstract: Dynamical mean-field theory allows access to the physics of strongly correlated materials with nontrivial orbital structure, but relies on the ability to solve auxiliary multi-orbital impurity problems. The most successful approaches to date for solving these impurity problems are the various continuous time quantum Monte Carlo algorithms. Here, we consider perhaps the simplest realization of multi-orbital physics: the bilayer Hubbard model on an infinite-coordination Bethe lattice. Despite its simplicity, the majority of this model's phase diagram cannot be predicted by using traditional Monte Carlo methods. We show that these limitations can be largely circumvented by recently introduced Inchworm Monte Carlo techniques. We then explore the model's phase diagram at a variety of interaction strengths, temperatures and filling ratios.