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arXiv · 1711.05235

Non-Hermitian robust edge states in one-dimension: Anomalous localization and eigenspace condensation at exceptional points

V. M. Martinez Alvarez·J. E. Barrios Vargas·L. E. F. Foa Torres
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Abstract

Capital to topological insulators, the bulk-boundary correspondence ties a topological invariant computed from the bulk (extended) states with those at the boundary, which are hence robust to disorder. Here we put forward an ordering unique to non-Hermitian lattices, whereby a pristine system becomes devoid of extended states, a property which turns out to be robust to disorder. This is enabled by a peculiar type of non-Hermitian degeneracy where a macroscopic fraction of the states coalesce at a single point with geometrical multiplicity of $1$, that we call a phenomenal point.

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V. M. Martinez Alvarez, J. E. Barrios Vargas, L. E. F. Foa Torres. 2017-11-14. Non-Hermitian robust edge states in one-dimension: Anomalous localization and eigenspace condensation at exceptional points. https://doi.org/10.1103/physrevb.97.121401

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