Scaling of the Anderson Lattice Model Studied by DMFT with CTQMC Impurity Solver

Abstract

The Kondo lattice model is known to be the minimal model for the heavy fermi liquid state of the heavy fermion systems. In spite of its fermi-liquid-like behaviour - T2 resistivity, T-linear specific heat, and T-independent spin susceptibility - its nature including the scaling relation of various physical quantities has not fully unveiled yet [1]. It is due to the fact that an analytic methodology based on the mean-field theory is limited to describe finitetemperature properties such as very incoherent spectrum near the Fermi level, and there is no concrete methodology for describing the strong coupling nature of the heavy fermion systems. On the other hand, DMFT is one of the most promising candidate for describing the strongly correlated system in a non-perturbative manner [2]. Using DMFT with numerically exact CTQMC impurity solver, we may perform a very well-controlled experiment on ideal model systems. In this work, we studied the Kondo lattice model by the dynamical mean-field theory (DMFT) with continuous time quantum Monte-Carlo (CTQMC) impurity solver [3]. As a result, we observed the scaling of various physical quantities such as the local spin susceptibility and scattering rate of the Kondo lattice model with different hybridisation strength and temperature. Compared with the Kondo impurity model, Kondo lattice shows different scaling energy scale due to the feedback effect of the DMFT. Additionally, temperature evolutions of the spectral properties such as the Fermi surface and band structure at the characteristic energy scale will be given. Discussion on how the feedback effect may change the RG beta function will be also given.