Microscopic Mechanism for Staggered Scalar Order in PrFe4P12

TL;DR

This paper presents a microscopic model explaining the scalar order in PrFe4P12 through interactions between f2 CEF states and conduction bands, highlighting the role of the Kondo effect in the ordered phase.

Contribution

It introduces a novel microscopic model combining DMFT and quantum Monte Carlo to explain scalar order and related properties in PrFe4P12, emphasizing the Kondo effect's importance.

Findings

The model reproduces the scalar order parameter and resistivity behavior.

It explains the field-induced staggered moment observed experimentally.

The ground state is semimetallic with different conduction band occupations.

Abstract

A microscopic model is proposed for the scalar order in PrFe4P12 where f2 crystalline electric field (CEF) singlet and triplet states interact with two conduction bands. By combining the dynamical mean-field theory and the continuous-time quantum Monte Carlo, we obtain an electronic order with staggered Kondo and CEF singlets with the total conduction number being unity per site. The ground state becomes semimetallic provided that the two conduction bands have different occupation numbers. This model naturally explains experimentally observed properties in the ordered phase of PrFe4P12 such as the scalar order parameter, temperature dependence of the resistivity, field-induced staggered moment, and inelastic features in neutron scattering. The Kondo effect plays an essential role for ordering, in strong contrast with ordinary magnetic orders by the RKKY interaction.