1209.5895v3.pdf (2.18 MB)
Kitaev anisotropy induces mesoscopic Z2 vortex crystals in frustrated hexagonal antiferromagnets
journal contribution
posted on 2018-08-06, 15:29 authored by Ioannis RousochatzakisIoannis Rousochatzakis, Ulrich K. Roessler, Jeroen van den Brink, Maria DaghoferThe triangular-lattice Heisenberg antiferromagnet (HAF) is known to carry topological Z2 vortex excitations which form a gas at finite temperatures. Here we show that the spin-orbit interaction, introduced via a Kitaev term in the exchange Hamiltonian, condenses these vortices into a triangular Z2 vortex crystal at zero temperature. The cores of the Z2 vortices show abrupt, soliton-like magnetization modulations and arise by a special intertwining of three honeycomb superstructures of ferromagnetic domains, one for each of the three sublattices of the 120 state of the pure HAF. This is an example of a nucleation transition, analogous to the spontaneous formation of magnetic domains, Abrikosov vortices in type-II superconductors, blue phases in cholesteric liquid crystals, and skyrmions in chiral helimagnets. As the mechanism relies on the interplay of geometric frustration and spin-orbital anisotropies, such vortex mesophases can materialize as a ground state property in spin-orbit coupled correlated systems with nearly hexagonal topology, as in triangular or strongly frustrated honeycomb iridates.
Funding
This research was sponsored by the Deutsche Forschungsgemeinschaft (DFG) under the Emmy-Noether Program (1235/1).
History
School
- Science
Department
- Physics
Published in
Physical Review BVolume
93Issue
10Citation
ROUSOCHATZAKIS, I. ... et al, 2016. Kitaev anisotropy induces mesoscopic Z2 vortex crystals in frustrated hexagonal antiferromagnets. Physical Review B, 93 (10), 104417.Publisher
© American Physical SocietyVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2016-03-17Notes
This paper was published in the journal Physical Review B and the definitive published version is available at https://doi.org/10.1103/PhysRevB.93.104417.ISSN
2469-9950eISSN
2469-9969Publisher version
Language
- en