Diabolical touching point in the magnetic energy levels of topological nodal-line metals
ORAL
Abstract
For three-dimensional metals, Landau levels disperse as a function of the magnetic field and the momentum wavenumber parallel to the field. In this two-dimensional parameter space, it is shown that two conically-dispersing Landau levels can touch at a diabolical point -- a Landau-Dirac point. The conditions giving rise to Landau-Dirac points are shown to be magnetic breakdown (field-driven quantum tunneling) and certain crystallographic spacetime symmetry. Both conditions are realizable in topological nodal-line metals, as we exemplify with SrAs3-family materials. A Landau-Dirac point reveals itself in anomalous "batman"-like peaks in the magnetoresistance, as well as in the onset of optical absorption linearly evolving to zero frequency as a function of the field magnitude/orientation.
*C.W. was supported by the Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division, Pro-QM EFRC (DE-SC0019443). Z.Z. and C.F. were supported by the Ministry of Science and Technology of China (2016YFA0302400), National Science Foundation of China (11674370), and Chinese Academy of Sciences (XXH13506-202, XDB33000000). A.A. was supported by the Gordon and Betty Moore Foundation EPiQS Initiative through Grant No. GBMF 4305 and GBMF 8691 at the University of Illinois.
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Presenters
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Chong Wang
- Department of Physics, Carnegie Mellon University
- Physics, Carnegie Mellon University
- Carnegie Mellon University
- Carnegie Mellon Univ