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arXiv · 1504.03069

A strong coupling theory for electron-mediated interactions in double-exchange models

Hiroaki Ishizuka·Yukitoshi Motome
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Abstract

We present a theoretical framework for evaluating effective interactions between localized spins mediated by itinerant electrons in double-exchange models. Performing the expansion with respect to the spin-dependent part of the electron hopping terms, we show a systematic way of constructing the effective spin model in the large Hund's coupling limit. As a benchmark, we examine the accuracy of this method by comparing the results with the numerical solutions for the spin-ice type model on a pyrochlore lattice. We also discuss an extension of the method to the double-exchange models with Heisenberg and $XY$ localized spins.

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Hiroaki Ishizuka, Yukitoshi Motome. 2015-04-13. A strong coupling theory for electron-mediated interactions in double-exchange models. https://doi.org/10.1103/physrevb.92.024415

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