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arXiv · 1107.1064

Absence of topological insulator phases in non-Hermitian PT-symmetric Hamiltonians

Yi Chen Hu·Taylor L. Hughes
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Abstract

In this work we consider a generalization of the symmetry classification of topological insulators to non-Hermitian Hamiltonians which satisfy a combined $PT$-symmetry (parity and time-reversal). We show via examples, and explicit bulk and boundary state proofs that the typical paradigm of forming topological insulator states from Dirac Hamiltonians is not compatible with the construction of non-Hermitian $PT$-symmetric Hamiltonians. The topological insulator states are $PT$-breaking phases and have energy spectra which are complex (not real) and thus such non-Hermitian Hamiltonians are not consistent quantum theories.

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Yi Chen Hu, Taylor L. Hughes. 2011-07-06. Absence of topological insulator phases in non-Hermitian PT-symmetric Hamiltonians. https://doi.org/10.1103/physrevb.84.153101

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