Spectral Asymmetry Induces a Re‐Entrant Quantum Hall Effect in a Topological Insulator

Autor: Li‐Xian Wang, Wouter Beugeling, Fabian Schmitt, Lukas Lunczer, Julian‐Benedikt Mayer, Hartmut Buhmann, Ewelina M. Hankiewicz, Laurens W. Molenkamp
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Advanced Science, Vol 11, Iss 19, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 2198-3844
DOI: 10.1002/advs.202307447
Popis: Abstract The band inversion of topological materials in three spatial dimensions is intimately connected to the parity anomaly of 2D massless Dirac fermions, known from quantum field theory. At finite magnetic fields, the parity anomaly reveals itself as a non‐zero spectral asymmetry, i.e., an imbalance between the number of conduction and valence band Landau levels, due to the unpaired zero Landau level. This work reports the realization of this 2D Dirac physics at a single surface of the 3D topological insulator (Hg,Mn)Te. An unconventional re‐entrant sequence of quantized Hall plateaus in the measured Hall resistance can be directly related to the occurrence of spectral asymmetry in a single topological surface state. The effect should be observable in any topological insulator where the transport is dominated by a single Dirac surface state.
Databáze: Directory of Open Access Journals
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