Field-Induced Ferrohastatic Phase In Cubic Non-Kramers Doublet Systems

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.