Origin of the large anisotropy in the χ3 Anomaly in URu 2Si2

Abstract

Motivated by recent quantum oscillations experiments on U Ru2Si2, we discuss the microscopic origin of the large anisotropy observed many years ago in the anomaly of the nonlinear susceptibility in this same material. We show that the magnitude of this anomaly emerges naturally from hastatic order, a proposal for hidden order that is a two-component spinor arising from the hybridization of a non-Kramers Γ5 doublet with Kramers conduction electrons. A prediction is made for the angular anisotropy of the nonlinear susceptibility anomaly as a test of this proposed order parameter for U Ru2Si2. © Published under licence by IOP Publishing Ltd.