Giant Anomalous Nernst Effect in Nodal Web Ferromagnets Fe<sub>3</sub><i>X</i> (<i>X</i> = Ga, Al)

ORAL

Abstract

Recently, large anomalous Hall effect (AHE) and anomalous Nernst effect (ANE) have been reported in topological magnets, where the large Berry curvature is induced by characteristic band crossings so-called Weyl points and nodal lines [1-4]. For example, Weyl ferromagnet Co2MnGa shows a large ANE ~6 μV/K at room temperature (T) [5]. This enables us to study thermoelectric applications by ANE, which has great potential such as efficient and flexible coverage of a heat source. For this purpose, substantial improvements are still necessary not only for the performance but also for the associated material costs, safety, and stability.

In this talk, we will present the newly discovered topological magnet Fe3X (X = Ga, Al) [6]. ANE for Fe3Ga and Fe3Al reaches ~5.5 μV/K and ~4 μV/K at room T, respectively. The transverse thermoelectric coefficient αxy reaches the record high value ~5.2 A/(Km) in Fe3Ga at ~200 K, originating from the nodal web structure near L point.

[1] S. Nakatsuji, N. Kiyohara, T. Higo, Nature 527, 212 (2015).
[2] N. Kiyohara et al., Phys. Rev. Applied 5, 064009 (2016).
[3] K. Kuroda, T. Tomita et al., Nat. Mater. 16, 1090 (2017).
[4] M. Ikhlas et al., Nat. Phys. 13, 1085 (2017).
[5] A. Sakai et al., Nat. Phys. 14, 1119 (2018).
[6] A. Sakai et al., Nature 581, 53 (2020).

–

Presenters

  • Akito Sakai

    • Univ of Tokyo

Authors

  • Akito Sakai

    • Univ of Tokyo

  • Susumu Minami

    • Univ of Tokyo

  • Takashi Koretsune

    • Tohoku Univ.
    • Tohoku University
    • Department of Physics, Tohoku University
    • Tohoku Univ

  • Taishi Chen

    • Univ of Tokyo
    • Institute for Solid State physics, University of Tokyo

  • Tomoya Higo

    • Univ of Tokyo
    • The Institute for Solid State physics, The Univeristy of Tokyo
    • University of Tokyo

  • Yangming Wang

    • Univ of Tokyo

  • Takuya Nomoto

    • Univ Tokyo
    • University of Tokyo
    • Univ of Tokyo
    • Department of Applied Physics, Univ of Tokyo
    • Department of Applied Physics, The University of Tokyo
    • Department of Applied Physics, University of Tokyo

  • Motoaki Hirayama

    • RIKEN
    • University of Tokyo
    • Center for Emergent Matter Science, RIKEN
    • CEMS, RIKEN
    • Quantum-Phase Electronics Center, The University of Tokyo

  • Shinji Miwa

    • Univ of Tokyo

  • Daisuke Nishio-Hamane

    • Univ of Tokyo

  • Fumiyuki Ishii

    • Kanazawa University

  • Ryotaro Arita

    • Univ of Tokyo
    • University of Tokyo
    • Department of Applied Physics, Univ of Tokyo
    • CEMS, RIKEN
    • Department of Applied Physics, The University of Tokyo
    • RIKEN-CEMS

  • Satoru Nakatsuji

    • Department of Physics and ISSP, University of Tokyo
    • Department of Physics, the University of Tokyo
    • Univ of Tokyo
    • Institute for Solid State Physics, University of Tokyo
    • The Institute for Solid State physics, The Univeristy of Tokyo
    • The Institute for Solid State Physics, The University of Tokyo
    • Institute for Solid State physics, University of Tokyo