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arXiv · 2307.16853

Spin-frame field theory of a three-sublattice antiferromagnet

Bastian Pradenas·Oleg Tchernyshyov
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Abstract

We present a nonlinear field theory of a three-sublattice hexagonal antiferromagnet. The order parameter is the spin frame, an orthogonal triplet of vectors related to sublattice magnetizations and spin chirality. The exchange energy, quadratic in spin-frame gradients, has three coupling constants, only two of which manifest themselves in the bulk. As a result, the three spin-wave velocities satisfy a universal relation. Vortices generally have an elliptical shape with the eccentricity determined by the Lam\'e parameters.

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Bastian Pradenas, Oleg Tchernyshyov. 2023-07-31. Spin-frame field theory of a three-sublattice antiferromagnet. https://doi.org/10.1103/physrevlett.132.096703

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