Critical and non critical non-Hermitian topological phase transitions in one dimensional chains

Abstract

In this work we investigate non-Hermitian topological phase transitions using real-space edge states as a paradigmatic tool. We focus on the simplest non-Hermitian variant of the Su-Schrieffer-Hegger model, including a parameter that denotes the degree of non-hermiticity of the system. We study the behavior of the zero energy edge states at the non-trivial topological phases with integer and semi-integer topological winding number, according to the distance to the critical point. We obtain that depending on the parameters of the model the edge states may penetrate into the bulk, as expected in Hermitian topological phase transitions. We also show that using the topological characterization of the exceptional points, we can describe the intricate chiral behavior of the edge states across the whole phase diagram. Moreover, we characterize the criticality of the model by determining the correlation length critical exponent, directly from numerical calculations of the penetration length of the zero modes edge states.

9 pages, 9 figures. Accepted for publication in PRB

References in corpus (7)

• Classification of topological insulators and superconductors in three spatial dimensions
• The physics of exceptional points
• Weyl Exceptional Rings in a Three-Dimensional Dissipative Cold Atomic Gas
• Flat Band in Disorder Driven Non-Hermitian Weyl Semimetals
• Universalities of thermodynamic signatures in topological phases
• Topology of multipartite non-Hermitian one-dimensional systems
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Cited by in corpus (5)

• Topological Non-Hermitian skin effect
• Anomalous pumping in the non-Hermitian Rice-Mele model
• Unconventional quantum criticality in a non-Hermitian extended Kitaev chain
• Exceptional Points, Bulk-Boundary Correspondence, and Entanglement Properties for a Dimerized Hatano-Nelson Model with Staggered Potentials
• Supercharging exceptional points: Full-spectrum pairwise coalescence in non-Hermitian systems