Toroidal order in a partially disordered state on a layered triangular lattice: implication to UNi4B

International Conference on Strongly Correlated Electron Systems 2014

Hayami, Satoru^1 ; Kusunose, Hiroaki^2 ; Motome, Yukitoshi^1

Department of Applied Physics, University of Tokyo, Tokyo

113-8656, Japan^1

Department of Physics, Ehime University, Matsuyama

790-8577, Japan^2

关键词: Layered triangular lattice;    Linear magnetoelectric effects;    Localized electrons;    Mean field approximation;    Parameter regions;    Partially disordered state;    Periodic Anderson model;    Spin-orbit couplings;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/592/1/012101/pdf
DOI  :  10.1088/1742-6596/592/1/012101

来源: IOP

【 摘 要 】

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.