Conductance of single-atom magnetic junctions: A first-principles study

Yi-qun Xie; Qiang Li; Lei Huang; Xiang Ye; San-Huang Ke

doi:10.1063/1.4766733

paper

Conductance of single-atom magnetic junctions: A first-principles study

arXiv:1210.4741 · doi:10.1063/1.4766733

Abstract

We present a first-principles investigation to show that the contact conductance of a half conductance quantum ( $G_{0} /2$ ) found previously does not generally hold for single-atom magnetic junctions composed of a tip and an adatom dsorbed on a surface. The contact conductance of the Ni-Co/Co(111) junction is approximately $G_{0} /2$ , while for the Co-Co/Co(111), Ni-Ni/Ni(111), and Ni-Ni/Ni(001) junctions the contact conductances are 0.80 $G_{0}$ , 1.55 $G_{0}$ , and 1.77 $G_{0}$ , respectively. The deviation from $G_{0} /2$ is mainly caused by the variation of the spin-down conductance largely determined by the minority $d$ orbitals, as the spin-up one changes little for different junctions.

4 pages, 4 figures