Collective Kondo effect in the Anderson-Hubbard lattice

TL;DR

This paper investigates how adding Hubbard interactions to conduction electrons in the Anderson lattice affects the Kondo effect, revealing a suppression of the Kondo scale and a transition from Kondo to Mott insulators.

Contribution

It introduces a study of the Anderson-Hubbard lattice using Gutzwiller variational method, highlighting the U-dependent effects on the Kondo energy and phase transitions.

Findings

U-dependent chemical potential influences the Kondo energy

Correlation effects cause band narrowing and suppress the Kondo scale

Transition from Kondo insulator to Mott insulator at half-filling

Abstract

The periodic Anderson model is extended by switching on a Hubbard U for the conduction electrons. We use the Gutzwiller variational method to study the nearly integral valent limit. The lattice Kondo energy contains the U-dependent chemical potential of the Hubbard subsystem in the exponent, and the correlation-induced band narrowing in the prefactor. Both effects tend to suppress the Kondo scale, which can be understood to result from the blocking of hybridization. At half-filling, we find a Brinkman-Rice-type transition from a Kondo insulator to a Mott insulator.