Limited robustness of edge magnetism in zigzag graphene nanoribbons with electrodes

Autor: Krompiewski, S.
Rok vydání: 2014
Předmět:
Zdroj: Nanotechnology 25 (2014) 465201
Druh dokumentu: Working Paper
DOI: 10.1088/0957-4484/25/46/465201
Popis: It is shown that apart from well-known factors, like temperature, substrate, and edge reconstruction effects, also the presence of external contacts is destructive for the formation of magnetic moments at the edges of graphene nanoribbons. The edge magnetism gradually decreases when graphene/electrode interfaces become more and more transparent for electrons. In addition to the graphene/electrode coupling strength, also the aspect ratio parameter, i.e. a width/length ratio of the graphene nanoribbon, is crucial for the suppression of edge magnetism. The present theory uses a tight-binding method, based on the mean-field Hubbard Hamiltonian for $\pi$ electrons, and the Green's function technique within the Landauer-B\"uttiker approach.
Comment: 8 pages, 6 figures
Databáze: arXiv