2003/03/31 by A. Bagrets, Alexei Bagrets, Nikos Papanikolaou +2 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Graphene research and applications #Molecular Junctions and Nanostructures #Semiconductor materials and interfaces #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.70.064410
published as Phys. Rev. B 70, 064410 (2004) · Revised version, presentation of results is improved, figure 2 is splitted to two figures
arxiv created 2004/05/17 · openalex publication_date 2004/08/18 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The magnetoresistance (MR) effect in metallic atomic-sized contacts is studied theoretically by means of first-principle electronic structure calculations. We consider three-atom chains formed from Co, Cu, Si, and Al atoms suspended between semi-infinite Co leads. We employ the screened Korringa-Kohn-Rostoker Green's function method for the electronic structure calculation and evaluate the conductance in the ballistic limit using the Landauer approach. The conductance through the constrictions reflects the spin-splitting of the Co bands and causes high MR ratios, up to 50%. The influence of the structural changes on the conductance is studied by considering different geometrical arrangements of atoms forming the chains. Our results show that the conductance through s-like states is robust against geometrical changes, whereas the transmission is strongly influenced by the atomic arrangement if p or d states contribute to the current.