Non-Hermitian Effects in the Su-Schrieffer-Heeger model: Exploring Substrate Coupling and Decoupling Dynamics

Abstract

The substrate-adsorbate interaction can significantly influence the adsorbate's electronic structure, stability, reactivity, and topological properties. In this study, we investigate the emergence of non-Hermitian physics in the Su-Schrieffer-Heeger (SSH) model when coupled to a substrate, focusing on the impact of substrate interaction on the electronic states of the adsorbate. We demonstrate how the coupling between the SSH chain and the underlying substrate induces non-Hermitian effects, which manifest as amplification or attenuation of zero-energy electronic states. Furthermore, inspired by novel experimental techniques such as using a scanning tunneling microscope tip to lift part of the nanomaterial, we present simulations of scenarios where a segment of the SSH chain is decoupled from the substrate. By examining various configurations, including cases with odd or even numbers of sites coupled to the substrate, we demonstrate that tuning the coupling strength induces novel phenomena, such as the emergence of a zero-energy monomode or additional zero-energy states localized at the boundary between on-surface and suspended chain segments. Our results reveal the role of substrate coupling in shaping the topological properties of non-Hermitian SSH chains, offering new insights into tunable non-Hermitian effects and their potential applications in quantum technologies and nanodevices.

References in corpus (33)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Making Sense of Non-Hermitian Hamiltonians
• Advances in atomic force microscopy
• Exceptional Topology of Non-Hermitian Systems
• On-surface synthesis of graphene nanoribbons with zigzag edge topology
• Biorthogonal Bulk-Boundary Correspondence in Non-Hermitian Systems
• Topological Band Theory for Non-Hermitian Hamiltonians
• Majorana Zero Modes and Topological Quantum Computation
• Anomalous edge state in a non-Hermitian lattice
• Non-Bloch Band Theory of Non-Hermitian Systems
• Non-Hermitian Chern bands
• Spawning rings of exceptional points out of Dirac cones
• Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator
• Topological Band Engineering of Graphene Nanoribbons
• Topological phases in the non-Hermitian Su-Schrieffer-Heeger model
• Quantum anomalous Hall effect and related topological electronic states
• Non-Hermitian Topological Invariants in Real Space
• Interplay between classical magnetic moments and superconductivity in quantum one-dimensional conductors: toward a self-sustained topological Majorana phase
• New topological invariants in non-Hermitian systems
• Non-Hermitian perspective of the band structure in heavy-fermion systems
• Symmetry-protected nodal phases in non-Hermitian systems
• Topological exceptional surfaces in non-Hermitian systems with parity-time and parity-particle-hole symmetries
• Tailoring topological order and π-conjugation to engineer quasi-metallic polymers
• Non-Hermitian topology: a unifying framework for the Andreev versus Majorana states controversy
• Topological phase transition in chiral graphene nanoribbons: from edge bands to end states
• Magnetism of topological boundary states induced by boron substitution in graphene nanoribbons
• Bright electroluminescence from single graphene nanoribbon junctions
• Knot topology of exceptional point and non-Hermitian no-go theorem
• Phase Transitions and Generalized Biorthogonal Polarization in Non-Hermitian Systems
• Breaking and resurgence of symmetry in the non-Hermitian Su-Schrieffer-Heeger model in photonic waveguides
• Pulling and Stretching a Molecular Wire to Tune its Conductance
• Fluorescent single-molecule STM probe