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arXiv · 1606.01952

Spin Nernst Effect of Magnons in Collinear Antiferromagnets

Ran Cheng·Satoshi Okamoto·Di Xiao
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Abstract

In a collinear antiferromagnet with easy-axis anisotropy, symmetry guarantees that the spin wave modes are doubly degenerate. The two modes carry opposite spin angular momentum and exhibit opposite chirality. Using a honeycomb antiferromagnet in the presence of the Dzyaloshinskii-Moriya interaction, we show that a longitudinal temperature gradient can drive the two modes to opposite transverse directions, realizing a spin Nernst effect of magnons with vanishing thermal Hall current. We find that magnons around the Γ-point and the K-point contribute oppositely to the transverse spin transport, and their competition leads to a sign change of the spin Nernst coefficient at finite temperature. Possible material candidates are discussed.

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Ran Cheng, Satoshi Okamoto, Di Xiao. 2016-11-15. Spin Nernst Effect of Magnons in Collinear Antiferromagnets. https://doi.org/10.1103/physrevlett.117.217202

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