An Auxiliary Field Quantum Monte Carlo study of the Hubbard Kanamori model

In the physics of strongly-correlated many-electron systems, the Hubbard Kanamori model has been extensively studied as a prototype for transition-metal oxides. The model is multiorbital in nature and contains Hund’s coupling terms. As a result, it may manifest metal-insulator transitions and high-temperature superconductivity. Due to the sign problem, it is mainly studied through the framework of Dynamical Mean-Field Theory (DMFT). We study the model using the ground state Auxiliary Field Quantum Monte Carlo (AFQMC) method. The Hubbard-Stratonovich transformation is applied to the Hund’s coupling and pair-exchange terms. The Constrained Path Approximation is used to control the sign problem. A systematic test is carried out on the accuracy of the approach. The ground state properties of the model will be discussed.