A partial disorder on a layered triangular lattice is theoretically investigated from a viewpoint of toroidal ordering and magnetoelectric effects. We consider an extended periodic Anderson model including a site-dependent antisymmetric spin-orbit coupling between conduction and localized electrons. We show that, by the mean-field approximation, the model exhibits a coplanar vortex-lattice-type magnetic order as observed in a hexagonal uranium compound UNi4B, in the parameter region with intermediate hybridization and electron correlation. This peculiar state accommodates a toroidal order, which leads to the linear magnetoelectric effect. We discuss the implications of our results to UNi4B, focusing on the possible source of the site-dependent antisymmetric spin-orbit coupling.
|Journal||Journal of Physics: Conference Series|
|Publication status||Published - 2014|
|Event||2014 International Conference on Strongly Correlated Electron Systems, SCES 2014 - Grenoble, France|
Duration: 7 Jul 2014 → 14 Jul 2014