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arXiv · 1308.1488

Calculation of Multipolar Exchange Interactions in Spin-Orbital Coupled Systems

Shu-Ting Pi·Ravindra Nanguneri·Sergey Savrasov
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Abstract

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.

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Shu-Ting Pi, Ravindra Nanguneri, Sergey Savrasov. 2013-08-07. Calculation of Multipolar Exchange Interactions in Spin-Orbital Coupled Systems. https://doi.org/10.1103/physrevlett.112.077203

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