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arXiv · 1912.10937

Non-Hermitian Dirac Cones

Haoran Xue·Qiang Wang·Baile Zhang·Y. D. Chong
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Abstract

Non-Hermitian systems, which contain gain or loss, commonly host exceptional point degeneracies rather than the diabolic points found in Hermitian systems. We present a class of non-Hermitian lattice models with symmetry-stabilized diabolic points, such as Dirac or Weyl points. They exhibit non-Hermiticity-induced phenomena previously existing in the Hermitian regime, including topological phase transitions, Landau levels induced by pseudo-magnetic fields, and Fermi arc surface states. These behaviors are controllable via gain and loss, with promising applications in tunable active topological devices.

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Haoran Xue, Qiang Wang, Baile Zhang, Y. D. Chong. 2019-12-23. Non-Hermitian Dirac Cones. https://doi.org/10.1103/physrevlett.124.236403

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