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arXiv · 0907.5070

Analysis of optical magnetoelectric effect in GaFeO_3

Jun-ichi Igarashi·Tatsuya Nagao
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Abstract

We study the optical absorption spectra in a polar ferrimagnet GaFeO_3. We consider the E1, E2 and M1 processes on Fe atoms. It is shown that the magnetoelectric effect on the absorption spectra arises from the E1-M1 interference process through the hybridization between the 4p and 3d states in the noncentrosymmetry environment of Fe atoms. We perform a microscopic calculation of the spectra on a cluster model of FeO_6 consisting of an octahedron of O atoms and an Fe atom displaced from the center with reasonable values for Coulomb interaction and hybridization. We obtain the magnetoelectric spectra, which depend on the direction of magnetization, as a function of photon energy in the optical region 1.0-2.5 eV, in agreement with the experiment.

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Jun-ichi Igarashi, Tatsuya Nagao. 2009-07-29. Analysis of optical magnetoelectric effect in GaFeO_3. https://doi.org/10.1103/physrevb.80.054418

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