In extended Heisenberg-Kitaev-Gamma-type spin models, hidden-SU(2)-symmetric points are isolated points in parameter space that can be mapped to pure Heisenberg models via nontrivial duality transformations. Such points generically feature quantum degeneracy between conventional single-q and exotic multi-q states. We argue that recent single-crystal inelastic neutron scattering data place the honeycomb magnet Na2Co2TeO6 in proximity to such a hidden-SU(2)-symmetric point. The low-temperature order is identified as a triple-q state arising from the Néel antiferromagnet with staggered magnetization in the out-of-plane direction via a 4-sublattice duality transformation. This state naturally explains various distinctive features of the magnetic excitation spectrum, including its surprisingly high symmetry and the dispersive low-energy and flat high-energy bands. Our result demonstrates the importance of bond-dependent exchange interactions in cobaltates, and illustrates the intriguing magnetic behavior resulting from them.
Description
Phys. Rev. Lett. 131, 146702 (2023) - Triple-q Order in ${\mathrm{Na}}_{2}{\mathrm{Co}}_{2}{\mathrm{TeO}}_{6}$ from Proximity to Hidden-SU(2)-Symmetric Point
%0 Journal Article
%1 PhysRevLett.131.146702
%A Krüger, Wilhelm G. F.
%A Chen, Wenjie
%A Jin, Xianghong
%A Li, Yuan
%A Janssen, Lukas
%D 2023
%I American Physical Society
%J Phys. Rev. Lett.
%K a
%N 14
%P 146702
%R 10.1103/PhysRevLett.131.146702
%T Triple-q order in Na$_2$Co$_2$TeO$_6$ from proximity to hidden-SU(2)-symmetric point
%U https://link.aps.org/doi/10.1103/PhysRevLett.131.146702
%V 131
%X In extended Heisenberg-Kitaev-Gamma-type spin models, hidden-SU(2)-symmetric points are isolated points in parameter space that can be mapped to pure Heisenberg models via nontrivial duality transformations. Such points generically feature quantum degeneracy between conventional single-q and exotic multi-q states. We argue that recent single-crystal inelastic neutron scattering data place the honeycomb magnet Na2Co2TeO6 in proximity to such a hidden-SU(2)-symmetric point. The low-temperature order is identified as a triple-q state arising from the Néel antiferromagnet with staggered magnetization in the out-of-plane direction via a 4-sublattice duality transformation. This state naturally explains various distinctive features of the magnetic excitation spectrum, including its surprisingly high symmetry and the dispersive low-energy and flat high-energy bands. Our result demonstrates the importance of bond-dependent exchange interactions in cobaltates, and illustrates the intriguing magnetic behavior resulting from them.
@article{PhysRevLett.131.146702,
abstract = {In extended Heisenberg-Kitaev-Gamma-type spin models, hidden-SU(2)-symmetric points are isolated points in parameter space that can be mapped to pure Heisenberg models via nontrivial duality transformations. Such points generically feature quantum degeneracy between conventional single-q and exotic multi-q states. We argue that recent single-crystal inelastic neutron scattering data place the honeycomb magnet Na2Co2TeO6 in proximity to such a hidden-SU(2)-symmetric point. The low-temperature order is identified as a triple-q state arising from the Néel antiferromagnet with staggered magnetization in the out-of-plane direction via a 4-sublattice duality transformation. This state naturally explains various distinctive features of the magnetic excitation spectrum, including its surprisingly high symmetry and the dispersive low-energy and flat high-energy bands. Our result demonstrates the importance of bond-dependent exchange interactions in cobaltates, and illustrates the intriguing magnetic behavior resulting from them.},
added-at = {2023-10-06T13:42:07.000+0200},
author = {Krüger, Wilhelm G. F. and Chen, Wenjie and Jin, Xianghong and Li, Yuan and Janssen, Lukas},
biburl = {https://www.bibsonomy.org/bibtex/2b269561c35181936865a2db1293af478/ctqmat},
day = 5,
description = {Phys. Rev. Lett. 131, 146702 (2023) - Triple-q Order in ${\mathrm{Na}}_{2}{\mathrm{Co}}_{2}{\mathrm{TeO}}_{6}$ from Proximity to Hidden-SU(2)-Symmetric Point},
doi = {10.1103/PhysRevLett.131.146702},
interhash = {436bf08f5c4bb740a6afabcb26715874},
intrahash = {b269561c35181936865a2db1293af478},
journal = {Phys. Rev. Lett.},
keywords = {a},
month = {10},
number = 14,
numpages = {8},
pages = 146702,
publisher = {American Physical Society},
timestamp = {2023-10-31T10:50:27.000+0100},
title = {Triple-q order in Na$_{\mathbf{2}}$Co$_{\mathbf{2}}$TeO$_{\mathbf{6}}$ from proximity to hidden-SU(2)-symmetric point},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.131.146702},
volume = 131,
year = 2023
}