Competition between Hund's coupling and Kondo effect in a one-dimensional extended periodic Anderson model

TL;DR

This paper investigates how Hund's coupling influences phase transitions in a one-dimensional extended periodic Anderson model, revealing complex ground states and phase boundaries through entanglement analysis.

Contribution

It introduces a detailed entanglement-based analysis of phase transitions caused by Hund's coupling and hybridization in a 1D extended periodic Anderson model.

Findings

Identification of two phase transitions with increasing hybridization.

Discovery of a dimerized intermediate phase.

Characterization of Haldane-like and Kondo-singlet-like phases.

Abstract

We study the ground-state properties of an extended periodic Anderson model to understand the role of Hund's coupling between localized and itinerant electrons using the density-matrix renormalization group algorithm. By calculating the von Neumann entropies we show that two phase transitions occur and two new phases appear as the hybridization is increased in the symmetric half-filled case due to the competition between Kondo-effect and Hund's coupling. In the intermediate phase, which is bounded by two critical points, we found a dimerized ground state, while in the other spatially homogeneous phases the ground state is Haldane-like and Kondo-singlet-like, respectively. We also determine the entanglement spectrum and the entanglement diagram of the system by calculating the mutual information thereby clarifying the structure of each phase.