Electronic Order with Staggered Kondo and Crystalline Electric Field Singlets

TL;DR

This paper theoretically predicts a novel electronic order involving alternating Kondo and CEF singlets in a specialized Kondo lattice model, revealing a charge density wave and potential relevance to PrFe$_4$P$_{12}$.

Contribution

It introduces a new electronic order with staggered Kondo and CEF singlets using advanced simulation methods, expanding understanding of correlated electron systems.

Findings

Identification of a staggered order with alternating Kondo and CEF singlets.

Charge density wave accompanying the electronic order.

Potential connection to scalar order in PrFe$_4$P$_{12}$.

Abstract

Novel electronic order is found theoretically for a system where even number of localized electrons per site are coupled with conduction electrons. For precise quantitative study, a variant of the Kondo lattice model is taken with crystalline electric field (CEF) singlet and triplet states for each site. Using the dynamical mean-field theory combined with the continuous-time quantum Monte Carlo method, a staggered order with alternating Kondo and CEF singlets is identified for a case with one conduction electron per site being distributed in two conduction bands each of which is quarter-filled. This electronic order accompanies a charge density wave (CDW) of conduction electrons that accumulate more on Kondo-singlet sites than on CEF-singlet sites. Possible relevance of the present order to the scalar order in PrFe$_4$P$_{12}$ is discussed.