%0 Journal Article %1 Hong2024 %A Hong, Xiaochen %A Gillig, Matthias %A Yao, Weiliang %A Janssen, Lukas %A Kocsis, Vilmos %A Gass, Sebastian %A Li, Yuan %A Wolter, Anja U. B. %A Büchner, Bernd %A Hess, Christian %D 2024 %J npj Quantum Mater. %K a %N 1 %P 18 %R 10.1038/s41535-024-00628-4 %T Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na$_2$Co$_2$TeO$_6$ %U https://doi.org/10.1038/s41535-024-00628-4 %V 9 %X The report of a half-quantized thermal Hall effect and oscillatory structures in the magnetothermal conductivity in the Kitaev material $\alpha$-RuCl3 have sparked a strong debate on whether it is generated by Majorana fermion edge currents, spinon Fermi surface, or whether other more conventional mechanisms are at its origin. Here, we report low temperature thermal conductivity ($\kappa$) of another candidate Kitaev material, Na2Co2TeO6. The application of a magnetic field (B) along different principal axes of the crystal reveals a strong directional-dependent B impact on $\kappa$, while no evidence for mobile quasiparticles except phonons can be concluded at any field. Instead, severely scattered phonon transport prevails across the B−T phase diagram, revealing cascades of phase transitions for all B directions. Our results thus cast doubt on recent proposals for significant itinerant magnetic excitations in Na2Co2TeO6, and emphasize the importance of discriminating true spin liquid transport properties from scattered phonons in candidate materials.

@article{Hong2024, abstract = {The report of a half-quantized thermal Hall effect and oscillatory structures in the magnetothermal conductivity in the Kitaev material $\alpha$-RuCl3 have sparked a strong debate on whether it is generated by Majorana fermion edge currents, spinon Fermi surface, or whether other more conventional mechanisms are at its origin. Here, we report low temperature thermal conductivity ($\kappa$) of another candidate Kitaev material, Na2Co2TeO6. The application of a magnetic field (B) along different principal axes of the crystal reveals a strong directional-dependent B impact on $\kappa$, while no evidence for mobile quasiparticles except phonons can be concluded at any field. Instead, severely scattered phonon transport prevails across the B−T phase diagram, revealing cascades of phase transitions for all B directions. Our results thus cast doubt on recent proposals for significant itinerant magnetic excitations in Na2Co2TeO6, and emphasize the importance of discriminating true spin liquid transport properties from scattered phonons in candidate materials.}, added-at = {2024-02-12T18:13:01.000+0100}, author = {Hong, Xiaochen and Gillig, Matthias and Yao, Weiliang and Janssen, Lukas and Kocsis, Vilmos and Gass, Sebastian and Li, Yuan and Wolter, Anja U. B. and Büchner, Bernd and Hess, Christian}, biburl = {https://www.bibsonomy.org/bibtex/22356ee3c741aa8660b26e86cf5af183d/ctqmat}, day = 10, description = {Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na2Co2TeO6 | npj Quantum Materials}, doi = {10.1038/s41535-024-00628-4}, interhash = {4de3693d572ca618036cc9ef4a926684}, intrahash = {2356ee3c741aa8660b26e86cf5af183d}, issn = {2397-4648}, journal = {npj Quantum Mater.}, keywords = {a}, month = {02}, number = 1, pages = 18, timestamp = {2024-02-23T10:19:49.000+0100}, title = {Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na$_{\mathbf{2}}$Co$_{\mathbf{2}}$TeO$_{\mathbf{6}}$}, url = {https://doi.org/10.1038/s41535-024-00628-4}, volume = 9, year = 2024 }