Electronic properties of atomic ribbons with spin-orbit couplings on different substrates

Abstract

Atomic ribbons and monoatomic chains on different substrates are proposed as spin-dependent electrical conductors with asymmetrical local density of states (DOS) and ferromagnetic occupancies along the chains. The tight-binding Hamiltonian and Green’s function techniques were used to analyze the electrical properties of both normal and topological systems with spin-orbit scattering. To make the system more realistic, electron leakage from atomic chains to various types of substrates is considered. We have shown that delocalized electrons in the substrate and spin-orbit interactions are responsible for asymmetry in the local DOS. The structure of DOS for spin-orbit nontopological chains is spin-dependent at both chain edges; however, in the middle of the chain, only paramagnetic solutions are observed. Additionally, we have found different periods of the local DOS oscillations along the chain in the presence of spin-flip and spin-orbit couplings. For topological chains, the edge nontrivial states split in the presence of spin-orbit scattering and spin-dependent Friedel oscillations appear along the whole topological chain. We have also found out-of-phase Friedel oscillations between neighboring chains along the atomic ribbon.