Exceptional Ising Magnetic Behavior of Itinerant Spin-polarized Carriers   in URu2Si2
  We show on the basis of electronic structure calculations that the uranium 5$f$ magnetic moment in URu$_2$Si$_2$ exhibits a unique Ising behavior, which surprisingly, arises from itinerant electronic states. The origin of the unusual Ising behavior is analyzed as due to the peculiar near-Fermi edge nested electronic structure of URu$_2$Si$_2$ involving its strong spin-orbit interaction. The Ising anisotropy has pertinent implications for theories applicable to explaining the Hidden Order phase in URu$_2$Si$_2$. 
Miroslaw Werwinski, Jan Rusz, John A. Mydosh, and Peter M. Oppeneer
cond-mat.str-el