Topology andPTsymmetry in a non-Hermitian Su-Schrieffer-Heeger chain with periodic hopping modulation
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Summary
This summary is machine-generated.Periodic hopping modulation in Su-Schrieffer-Heeger chains with imaginary potentials modifies topological phases. Real or imaginary in-gap states emerge, with edge states showing extended behavior and bulk states localizing with dimerization and potential strength.
Area Of Science
- Condensed Matter Physics
- Topological Materials
- Quantum Mechanics
Background
- The Su-Schrieffer-Heeger (SSH) model describes topological phases in 1D systems.
- Non-Hermitian (NH) extensions introduce dissipation and can break parity-time (PT) symmetry.
- Periodic hopping modulation can introduce in-gap states even without dissipation.
Purpose Of The Study
- To investigate the impact of periodic hopping modulation and staggered imaginary potentials on SSH chains.
- To analyze the modification of topological trivial and nontrivial phases under these conditions.
- To explore the nature and localization of in-gap, edge, and bulk states.
Main Methods
- Theoretical study of a modified SSH chain incorporating periodic hopping and an onsite staggered imaginary potential.
- Analysis of energy eigenvalues (real/imaginary) and state localization.
- Investigation of the system's behavior across different dimerization strengths (Δ) and potential strengths (γ).
Main Results
- Non-zero energy in-gap states exhibit purely real or imaginary eigenvalues dependent on γ and Δ.
- Topological edge states display extended characteristics near topological transitions and the unmodulated limit (Δ=0).
- Bulk states localize at maximum dimerization (|Δ/t|=1), with localization increasing with γ.
Conclusions
- The interplay of periodic hopping and imaginary potentials significantly alters topological phase properties in SSH chains.
- Dissipative features offer tunability for optical systems (gain-loss contrast) and quantum device design.
- The study reveals novel state localization phenomena driven by dissipation and dimerization.
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