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arXiv · 1006.5279

Effects of Anisotropic Charge on Transverse Optical Phonons in NiO

H. Uchiyama·S. Tsutsui·A. Q. R Baron
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Abstract

Phonon dispersion of detwinned NiO is measured using inelastic x-ray scattering. It is found that, near the zone center, the energy of the transverse optical phonon mode polarized parallel to the antiferromagnetic order is ~1 meV lower than that of the mode polarized perpendicular to the order, at room temperature. This is explained via anisotropic polarization of the Ni and O atoms, as confirmed using a Berry's phase approach with first-principles calculations. Our explanation avoids an apparent contradiction in previous discussions focusing on Heisenberg interaction.

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H. Uchiyama, S. Tsutsui, A. Q. R Baron. 2010-06-28. Effects of Anisotropic Charge on Transverse Optical Phonons in NiO. https://arxiv.org/abs/1006.5279

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