Topology and exceptional points of massive Dirac models with generic non-Hermitian perturbations

Abstract

Recently, there has been a lot of activity in the research field of topological non-Hermitian physics, partly driven by fundamental interests and partly driven by applications in photonics. However, despite these activities, a general classification and characterization of non-Hermitian Dirac models that describe the experimental systems is missing. Here, we present a systematic investigation of massive Dirac models on periodic lattices, perturbed by general non-Hermitian terms. We find that there are three different types of non-Hermitian terms. For each case we determine the bulk exceptional points, the boundary modes, and the band topology. Our findings serve as guiding principles for the design of applications, for example, in photonic lattices. For instance, periodic Dirac systems with non-Hermitian mass terms can be used as topological lasers. Periodic Dirac systems with non-Hermitian anti-commuting terms, on the other hand, exhibit exceptional points at the surface, whose non-trivial topology could be utilized for optical devices.

arXiv comment6 pages, 2 figures + 4 pages of supplemental material

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Cited by in corpus (36)

• Exceptional Topology of Non-Hermitian Systems
• Non-Hermitian skin effect and chiral damping in open quantum systems
• Non-Hermitian Topological Invariants in Real Space
• Classification of Exceptional Points and Non-Hermitian Topological Semimetals
• Second-order topological non-Hermitian skin effects
• Mirror skin effect and its electric circuit simulation
• Topological classification of defects in non-Hermitian systems
• Non-Hermitian Floquet topological superconductors with multiple Majorana edge modes
• Topological Bose-Mott insulators in one-dimensional non-Hermitian superlattices
• Dynamical characterization of non-Hermitian Floquet topological phases in one-dimension
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• Controlling Exceptional Points with Light
• Diagnosis of bulk phase diagram of non-reciprocal topological lattices by impurity modes
• Anatomy of open-boundary bulk in multiband non-Hermitian systems
• Non-Hermitian spatial symmetries and their stabilized normal and exceptional topological semimetals
• Degeneracy and defectiveness in non-Hermitian systems with open boundary
• Probing non-Hermitian phase transitions in curved space via quench dynamics
• Machine learning non-Hermitian topological phases
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• Hermitian Topologies originating from non-Hermitian braidings
• Defective Edge states and Anomalous Bulk-boundary Correspondence for Topological Insulators under Non-Hermitian Similarity Transformation
• Braids and Higher-order Exceptional Points from the Interplay Between Lossy Defects and Topological Boundary States
• Visualizing Topology of Real-Energy Gapless Phase Arising from Exceptional Point
• Inverse Design of Winding Tuple for Non-Hermitian Topological Edge Modes
• Exceptional Non-Hermitian Topology Associated with Non-Toroidal Brillouin Zones
• Non-Hermitian Higher-Order Dirac Semimetals