Field-induced Ferrohastatic Order in Cubic Non-Kramers Doublet Systems

TL;DR

This paper introduces a microscopic model and Landau theory for ferrohastatic order in cubic non-Kramers doublet systems, explaining experimental heavy Fermi liquids in Pr-based compounds under magnetic fields.

Contribution

It develops a realistic microscopic model and thermodynamic framework for ferrohastatic order, linking theory with experimental observations in Pr-based heavy Fermi liquids.

Findings

Ferrohastatic order explains heavy Fermi liquids in Pr(Ir,Rh)₂Zn₂₀.

The model predicts experimental signatures in magnetic susceptibility and thermal expansion.

Field behavior of ferrohastatic order aligns with observed intermediate-field phases.

Abstract

Cubic Pr-based compounds with $\Gamma_3$ non-Kramers doublet ground states can realize a novel heavy Fermi liquid with spinorial hybridization ('hastatic' order) that breaks time reversal symmetry. Several Pr-"1-2-20" materials exhibit a suggestive heavy Fermi liquid stabilized in intermediate magnetic fields; these provide key insight into the quadrupolar Kondo lattice. We develop a simple, yet realistic microscopic model of ferrohastatic order, and elaborate its experimental signatures and behavior in field, where it is a good candidate to explain the observed heavy Fermi liquids at intermediate fields in Pr(Ir,Rh)$_2$Zn$_{20}$. In addition, we develop the Landau theory of ferrohastatic order, which allows us to understand its behavior close to the transition and explore thermodynamic signatures from magnetic susceptibility to thermal expansion.