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arXiv · 2012.11604

Symmetry Analysis of Tensors in the Honeycomb Lattice of Edge-Sharing Octahedra

Franz G. Utermohlen·Nandini Trivedi
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Abstract

We obtain the most general forms of rank-2 and rank-3 tensors allowed by the crystal symmetries of the honeycomb lattice of edge-sharing octahedra for crystals belonging to different crystallographic point groups, including the monoclinic point group $2/m$ and the trigonal (or rhombohedral) point group $\bar{3}$. Our results are relevant for two-dimensional materials, such as $\alpha$-RuCl$_3$, CrI$_3$, and the honeycomb iridates. We focus on the magnetic-field-dependent thermal conductivity tensor $\kappa_{ij}(\mathbf{H})$, which describes a system's longitudinal and thermal Hall responses, for the cases when the magnetic field is applied along high-symmetry directions, perpendicular to the plane and in the plane. We highlight some unexpected results, such as the equality of fully-longitudinal components to partially-transverse components in rank-3 tensors for systems with three-fold rotational symmetry, and make testable predictions for the thermal conductivity tensor.

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Franz G. Utermohlen, Nandini Trivedi. 2020-12-21. Symmetry Analysis of Tensors in the Honeycomb Lattice of Edge-Sharing Octahedra. https://doi.org/10.1103/physrevb.103.155124

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