Topological Atomic Chains on 2D Hybrid Structure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• 1D topological states exhibit unique electronic properties.
• Su-Schrieffer-Heeger (SSH) models describe topological phenomena in 1D systems.
• The influence of realistic 2D substrates on these states is not fully understood.

Purpose of the Study:

• To investigate mid-gap 1D topological states in SSH chains coupled with 2D hybrid structures.
• To analyze the electronic properties and spectral density of these coupled systems.
• To understand how 2D substrates modify topological states compared to ideal electrodes.

Main Methods:

• Utilizing the tight-binding Hamiltonian formalism.
• Employing the Green's function technique for electronic structure calculations.
• Analyzing density of states (DOS) and local DOS of SSH chains on 2D substrates.

Main Results:

• 2D substrates induce significant asymmetry in on-site energies and local DOS of topological states.
• Surface singularities cause splitting, localization, and dispersionless behavior of SSH topological states.
• Topological edge states appear at different energies for zig-zag and armchair configurations due to spatial asymmetry.

Conclusions:

• Realistic 2D hybrid structures profoundly impact 1D topological states, leading to novel phenomena.
• These effects are distinct from those observed with ideal wide-band electrodes.
• The findings highlight the importance of substrate interactions in designing topological electronic devices.