Effective Low-Energy Model for f-Electron Delocalization

TL;DR

This paper derives an effective low-energy model for f-electron systems with momentum-dependent hybridization, revealing a doping-induced Mott transition in f-electron delocalization through DMRG analysis.

Contribution

It introduces a simplified low-energy Hamiltonian capturing f-electron delocalization, incorporating a momentum-dependent hybridization and Kondo coupling, and demonstrates a Mott transition.

Findings

Identification of a doping-induced Mott transition for f-electron delocalization.

Development of an effective Hamiltonian with a t-J f-band and Kondo coupling.

Validation of the model using DMRG calculations.

Abstract

We consider a Periodic Anderson Model (PAM) with a momentum-dependent inter-band hybridization that is strongly suppressed near the Fermi level. Under these conditions, we reduce the PAM to an effective low-energy Hamiltonian, $H_{\rm eff}$, by expanding in the small parameter $V_0/t$ ( $V_0$ is the maximum inter-band hybridization amplitude and $t$ is the hopping integral of the broad band). The resulting model consists of a t-J f-band coupled via the Kondo exchange to the electrons in the broad band. $H_{\rm eff}$ allows for studying the f-electron delocalization transition. The result is a doping-induced Mott transition for the f-electron delocalization, which we demonstrate by density-matrix renormalization group (DMRG) calculations.