%0 Journal Article
%T Calculation of Multipolar Exchange Interactions in Spin-Orbital Coupled Systems
%A Shu-Ting Pi
%A Ravindra Nanguneri
%A Sergey Savrasov
%J Physics
%D 2013
%I arXiv
%R 10.1103/PhysRevLett.112.077203
%X A new method of computing multipolar exchange interaction in spin-orbit coupled systems is developed using multipolar tensor expansion of the density matrix in LDA+U electronic structure calculation. Within mean-field approximation, exchange constants can be mapped into a series of total energy calculations by pair-flip technique. Application to Uranium dioxide shows an antiferromagnetic superexchange coupling in dipoles but ferromagnetic in quadrupoles which is very different from past studies. Further calculation of spin-lattice interaction indicates it is of the same order with superexchange and characterizes the overall behavior of quadrupolar part as a competition between them.
%U http://arxiv.org/abs/1308.1488v1