Thermal Hall effect of Kitaev quantum spin liquid candidate materials

ORAL  · Invited

Abstract

α-RuCl3 represents one of the most intriguing quantum materials of the past years. Numerous evidence for a significant Kitaev interaction between the j=1/2 moments which are located at the vertices of a honeycomb lattice has nourished hope to find fingerprints of the celebrated Kitaev model in this compound. Indeed, reports of a half-quantized thermal Hall effect in α-RuCl3 seem to match perfectly with the predicted thermal transport due to an emergent Majorana edge mode of the Kitaev quantum spin liquid (QSL). On the other hand, we have demonstrated that the longitudinal thermal transport of α-RuCl3 is due to phonons and is determined by a strong phonon-spin scattering. Interestingly, its temperature dependence is very similar to that of the thermal Hall conductivity which suggests the possibility of an alternative phononic scenario for the thermal Hall effect. Recently, Na2Co2TeO6 emerged as a new and interesting candidate materials for a Kitaev QSL. Our data for the longitudinal thermal conductivity reveal a striking similarity to that of α-RuCl3, as well as a large thermal Hall effect. Thus, with these two materials at hand, one can hope to obtain fresh information as to whether the thermal Hall effect in the Kitaev QSL compounds is due to genuine Majorana heat transport or due to to phonons.

*This work has been supported by the Deutsche Forschungsgemeinschaft through SFB 1143 (Project No. 247310070), the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter-ct.qmat (EXC 2147, Project No. 390858490).This work has further been supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 647276-MARS-ERC-2014-CoG).Work at Peking University was supported by the NSF of China (NSFC) under Grant No. 11888101, and by the National Basic Research Program of China under Grant No. 2018YFA0305602.

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Publication: Strongly scattered phonon heat transport of the candidate Kitaev material Na2Co2TeO6, Xiaochen Hong, Matthias Gillig, Richard Hentrich, Weiliang Yao, Vilmos Kocsis, Arthur R. Witte, Tino Schreiner, Danny Baumann, Nicolás Pérez, Anja U. B. Wolter, Yuan Li, Bernd Büchner, and Christian Hess, Phys. Rev. B 104, 144426 (2021)

High-field thermal transport properties of the Kitaev quantum magnet α-RuCl3: Evidence for low-energy excitations beyond the critical field, Richard Hentrich, Xiaochen Hong, Matthias Gillig, Federico Caglieris, Matija Čulo, Maryam Shahrokhvand, Uli Zeitler, Maria Roslova, Anna Isaeva, Thomas Doert, Lukas Janssen, Matthias Vojta, Bernd Büchner, and Christian Hess, Phys. Rev. B 102, 235155 (2020)

Unusual Phonon Heat Transport in α-RuCl3: Strong Spin-Phonon Scattering and Field-Induced Spin Gap, Richard Hentrich, Anja U. B. Wolter, Xenophon Zotos, Wolfram Brenig, Domenic Nowak, Anna Isaeva, Thomas Doert, Arnab Banerjee, Paula Lampen-Kelley, David G. Mandrus, Stephen E. Nagler, Jennifer Sears, Young-June Kim, Bernd Büchner, and Christian Hess, Phys. Rev. Lett. 120, 117204 (2018)

Large thermal Hall effect in α-RuCl3: Evidence for heat transport by Kitaev-Heisenberg paramagnons, Richard Hentrich, Maria Roslova, Anna Isaeva, Thomas Doert, Wolfram Brenig, Bernd Büchner, and Christian Hess, Phys. Rev. B 99, 085136 (2019)

Presenters

  • Christian Hess

    • University of Wuppertal
    • IFW-Dresden

Authors

  • Christian Hess

    • University of Wuppertal
    • IFW-Dresden

  • Xiao-Chen Hong

    • University of Wuppertal

  • Matthias Gillig

    • IFW Dresden, Germany
    • IFW Dresden

  • Richard Hentrich

    • IFW Dresden

  • Anja U Wolter

    • IFW Dresden

  • Vilmos Kocsis

    • IFW Dresden

  • Bernd Büchner

    • IFW Dresden
    • Institut für Festkörperphysik and Würzburg-Dresden Cluster of Excellence ct.qmat, Technische Universität Dresden

  • Federico Caglieris

    • IFW Dresden

  • Maria Roslova

    • TU Dresden

  • Anna Isaeva

    • Institute of Physics, University of Amsterdam, The Netherlands
    • University of Amsterdam

  • Thomas Doert

    • TU Dresden

  • Weiliang Yao

    • Peking Univ

  • Yuan Li

    • Peking Univ

  • Wolfram Brenig

    • Tech Univ Braunschweig