Weyl Fermion magneto-electrodynamics and ultralow field quantum limit in TaAs.
Sci Adv
; 8(2): eabj1076, 2022 Jan 14.
Article
em En
| MEDLINE
| ID: mdl-35030016
ABSTRACT
Topological semimetals are predicted to exhibit unconventional electrodynamics, but a central experimental challenge is singling out the contributions from the topological bands. TaAs is the prototypical example, where 24 Weyl points and 8 trivial Fermi surfaces make the interpretation of any experiment in terms of band topology ambiguous. We report magneto-infrared reflection spectroscopy measurements on TaAs. We observed sharp inter-Landau level transitions from a single pocket of Weyl Fermions in magnetic fields as low as 0.4 tesla. We determine the W2 Weyl point to be 8.3 meV below the Fermi energy, corresponding to a quantum limitthe field required to reach the lowest LLof 0.8 teslaunprecedentedly low for Weyl Fermions. LL spectroscopy allows us to isolate these Weyl Fermions from all other carriers in TaAs, and our result provides a way for directly exploring the more exotic quantum phenomena in Weyl semimetals, such as the chiral anomaly.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Sci Adv
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos