We theoretically investigate a pure spin Hall current driven by a longitudinal temperature gradient, i.e., the spin Nernst effect (SNE), in a paramagnetic state of a collinear antiferromagnetic insulator with the Dzyaloshinskii-Moriya interaction. The SNE in a magnetic ordered state in such an insulator was proposed by Cheng {\it et al.} [R. Cheng, S. Okamoto, and D. Xiao, Phys. Rev. Lett. 117, 217202 (2016)]. Here we show that the Dzyaloshinskii-Moriya interaction can generate a pure spin Hall current even without magnetic ordering. By using a Schwinger boson mean-field theory, we calculate the temperature dependence of SNE in a disordered phase. We also discuss the implication of our results to experimental realizations.
@article{arxiv.1807.07631,
title = {Spin Nernst effect in the Paramagnetic Regime of An Antiferromagnetic Insulator},
author = {Yinhan Zhang and Satoshi Okamoto and Di Xiao},
journal= {arXiv preprint arXiv:1807.07631},
year = {2018}
}