Spectral analysis, chiral disorder and topological edge states manifestation in open non-Hermitian Su-Schrieffer-Heeger chains

Abstract

We investigate topological and disorder effects in non-Hermitian systems with chiral symmetry. The system under consideration consists in a finite Su-Schrieffer-Heeger chain to which two semi-infinite leads are attached. The system lacks the parity-time and time-reversal symmetries and is appropriate for the study of quantum transport properties. The complex energy spectrum is analyzed in terms of the chain-lead coupling and chiral disorder strength, and shows substantial differences between chains with even and odd number of sites. The mid-gap edge states acquire a finite lifetime and are both of topological origin or generated by a strong coupling to the leads. The disorder induces coalescence of the topological eigenvalues, associated with exceptional points and vanishing of the eigenfunction rigidity. The electron transmission coefficient is approached in the Landauer formalism, and an analytical expression for the transmission in the range of topological states is obtained. Notably, the chiral disorder in this non-Hermitian system induces unitary conductance enhancement in the topological phase.

arXiv comment25 pages,12 figures

References in corpus (22)

• Real Spectra in Non-Hermitian Hamiltonians Having PT Symmetry
• Classification of topological insulators and superconductors in three spatial dimensions
• Making Sense of Non-Hermitian Hamiltonians
• Novel Symmetry Classes in Mesoscopic Normal-Superconducting Hybrid Structures
• Edge states and topological invariants of non-Hermitian systems
• Biorthogonal Bulk-Boundary Correspondence in Non-Hermitian Systems
• Anomalous edge state in a non-Hermitian lattice
• Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems
• Topological Anderson Insulator
• Selective enhancement of topologically induced interface states in a dielectric resonator chain
• Observation of the topological Anderson insulator in disordered atomic wires
• New topological invariants in non-Hermitian systems
• Topological Criticality in the Chiral-Symmetric AIII Class at Strong Disorder
• Topological characterizations of an extended Su-Schrieffer-Heeger model
• Interplay between long range hopping and disorder in topological systems
• Generalized bulk-edge correspondence for non-hermitian topological systems
• Topology vs. Anderson localization: non-perturbative solutions in one dimension
• Coexisting edge states and gapless bulk in topological states of matter
• Non-Hermitian approach of edge states and quantum transport in a magnetic field
• Coulomb effects on the transport properties of quantum dots in strong magnetic field
• Photonic topological insulators induced by non-Hermitian disorders in a coupled-cavity array
• Edge states mechanism for the anomalous quantum Hall effect in diatomic square lattice

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• Exceptional Non-Hermitian Phases in Disordered Quantum Wires
• Mesoscopic transport signatures of disorder-induced non-Hermitian phases
• Scanning qubit probe of edge states in a topological insulator
• Dissipation Enhanced Unidirectional Transport in Topological Systems
• Scattering description of edge states in Aharonov-Bohm triangle chains
• Supercharging exceptional points: Full-spectrum pairwise coalescence in non-Hermitian systems
• Topological edge states of the hexagonal linear chain
• A General Algorithm For Determining The Conductivity Zeros In Large Molecular Nanostructures: Applications To Rectangular Graphene Sheets