Synthesis of a semimetallic Weyl ferromagnet, (Cr,Bi)<sub>2</sub>Te<sub>3</sub>

ORAL

Abstract

Quantum materials governed by emergent topological fermions have become a cornerstone of physics. However, there are few materials whose electromagnetic response is dominated by emergent Weyl fermions. Nearly all known Weyl materials are overwhelmingly metallic, and are largely governed by irrelevant, conventional electrons [1-4]. Here we theoretically predict and experimentally observe a semimetallic Weyl ferromagnet in (Cr,Bi)2Te3 [5]. In transport, we find a record bulk anomalous Hall angle > 0.5 along with non-metallic conductivity, a regime sharply distinct from conventional ferromagnets and known Weyl materials. Together with symmetry analysis, our data suggest a semimetallic Fermi surface composed of two Weyl points, with a giant separation > 75% of the linear dimension of the bulk Brillouin zone, and no other electronic states. Using state-of-the-art molecular beam epitaxy, we widely tune the electronic structure, allowing us to annihilate the Weyl state and visualize a Murakami-like topological phase diagram. Our semimetallic Weyl ferromagnet provides a unique platform for Weyl superconductors, Weyl thermoelectrics and neuromorphic computing [6].



[1] Hasan, Chang, Belopolski et al., Nat. Rev. Mat. 6, 784 (2021).

[2] Belopolski et al., Nature 604, 647 (2022).

[3] Belopolski et al., Science 365, 1278 (2019).

[4] Tokura, Yasuda and Tsukazaki, Nat. Rev. Phys. 1, 126 (2019).

[5] Belopolski et al., Nature, in press.

[6] Sato, Nagahama, Belopolski et al., Phys. Rev. Mat. 8, L041801 (2024).

–

Publication: I. Belopolski et al. Nature, in press.

Presenters

  • Ilya Belopolski

    • RIKEN

Authors

  • Ilya Belopolski

    • RIKEN

  • Ryota Watanabe

    • Univ of Tokyo

  • Yuki Sato

    • RIKEN

  • Ryutaro Yoshimi

    • Department of Advanced Materials Science, The University of Tokyo

  • Minoru Kawamura

    • RIKEN Center for Emergent Matter Science (CEMS)

  • Soma Nagahama

    • University of Tokyo

  • Yilin Zhao

    • Nanyang Technological University

  • Sen Shao

    • Nanyang Technological University

  • Yuanjun JIN

    • Nanyang Technological University

  • Yoshihiro Kato

    • University of Tokyo

  • Yoshihiro Okamura

    • Univ of Tokyo
    • The University of Tokyo

  • Xiao-Xiao Zhang

    • RIKEN

  • Yukako Fujishiro

    • RIKEN Center for Emergent Matter Science (CEMS)
    • RIKEN

  • Youtarou Takahashi

    • Univ of Tokyo, RIKEN
    • University of Tokyo
    • The University of Tokyo

  • Max Hirschberger

    • Univ of Tokyo
    • University of Tokyo

  • Atsushi Tsukazaki

    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo
    • Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo

  • Kei S Takahashi

    • RIKEN

  • Ching-Kai Chiu

    • RIKEN iTHEMS

  • Guoqing Chang

    • Nanyang Technological University

  • Masashi Kawasaki

    • RIKEN Center for Emergent Matter Science (CEMS), Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo
    • RIKEN Center for Emergent Matter Science (CEMS), Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo

  • Naoto Nagaosa

    • RIKEN Center for Emergent Matter Science (CEMS)

  • Yoshinori Tokura

    • RIKEN Center for Emergent Matter Science (CEMS), Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo
    • Univ of Tokyo
    • The University of Tokyo, RIKEN Center for Emergent Matter Science (CEMS), Tokyo college, The University of Tokyo
    • RIKEN Center for Emergent Matter Science (CEMS); Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo; Tokyo College, Univ. of Tokyo
    • RIKEN Center for Emergent Matter Science (CEMS), Department of Applied Physics, Quantum-Phase Electronics Center (QPEC) and Tokyo College, University of Tokyo