Continuous ferromagnetic quantum phase transition on an anisotropic Kondo lattice

TL;DR

This paper develops a tensor network algorithm to study ferromagnetic quantum phase transitions in an anisotropic Kondo lattice, revealing how magnetic anisotropy influences the nature of the transition and explaining experimental findings in CeRh$_6$Ge$_4$.

Contribution

It introduces a numerical tensor network method to analyze anisotropic ferromagnetic Kondo lattices and uncovers the role of anisotropy in quantum criticality.

Findings

Continuous quantum phase transition in large anisotropy regime

First-order transition at smaller anisotropy levels

Magnetic anisotropy significantly affects ferromagnetic quantum criticality

Abstract

Motivated by the recent discovery of ferromagnetic quantum criticality in the heavy fermion compound CeRh$_6$Ge$_4$, we develop a numerical algorithm of infinite projected entangled pair states for the anisotropic ferromagnetic Kondo-Heisenberg model in two dimensions and study the ferromagnetic quantum phase transitions with varying magnetic and hopping anisotropy. Our calculations reveal a continuous ferromagnetic quantum phase transition in the large anisotropic region and first-order quantum phase transitions for smaller anisotropy. Our results highlight the importance of magnetic anisotropy on ferromagnetic quantum criticality in Kondo lattice systems and provide a possible explanation for the experimental observation in CeRh$_6$Ge$_4$ with a quasi-one-dimensional magnetic structure. Our work opens the avenue for future studies of the rich Kondo lattice physics using state-of-the-art tensor network approaches.