Topology induced Kondo effect in hydrogenated Pt nanocontacts

TL;DR

This paper explains the observed topological Kondo effect in hydrogenated platinum nanocontacts through an exact solution of a model Hamiltonian, revealing how hydrogen influences conductance at the quantum level.

Contribution

It introduces a model Hamiltonian incorporating Pt and hydrogen orbitals with electron-electron interactions, explaining experimental conductance data.

Findings

Kondo effect stabilizes conductance around one quantum.

Single-channel conductance consistent with experiments.

Topological and correlation effects explain transport phenomena.

Abstract

It is shown that recent experimental data on electronic transport through Pt nanocontacts in the presence of hydrogen admit an explanation in terms of topological and electron-electron correlation grounds. A model Hamiltonian, which incorporates two orbitals on Pt atoms, a single orbital on hydrogens, and the on-site Coulomb repulsion on the H atoms, is solved exactly, and connected to Pt leads described by a Bethe lattice. When two weakly coupled H atoms are placed between the Pt electrodes transversally to the transport direction (as recently suggested) a Kondo effect related to the symmetry of the Pt-H couplings, stabilizes the conductance around one quantum with a single channel contributing to the current, in agreement with the experiments.