Document Type


Original Publication Date


Journal/Book/Conference Title

The Journal of Chemical Physics





DOI of Original Publication



Originally published at

Date of Submission

October 2015


Electronic transport across a FeMg8 magnetic superatom and its dimer has been investigated using a density functional theory combined with Keldysh nonequilibrium Green's-function formalism. For a single cluster, our studies for the cluster supported in various orientations on a Au(100) surface show that the transport is sensitive to the contact geometry. Investigations covering the cases where the axes of Mg square antiprism are 45°, perpendicular, and parallel to the transport direction, show that the equilibrium conductance, transferred charge, and currentpolarizations can all change significantly with orientation. Our studies on the transport across a magnetic superatom dimer FeMg8–FeMg8 focus on the effect of electrode contact distance and the support. The calculated I-V curves show negative differential resistance behavior at larger electrode-cluster contact distances. Further, the equilibrium conductance in ferromagnetic state shows an unusually high spin polarization that is about 81.48% for specific contact distance, and a large magnetoresistance ratio exceeding 500% is also found. The results show that the superatom assemblies can provide unusual transport characteristics, and that the spinpolarization and magnetoresistance can be controlled via the contact geometry.


Zhu, L., Qian, M., & Khanna, S. N. Unusually large spin polarization and magnetoresistance in a FeMg8-FeMg8 superatomic dimer. The Journal of Chemical Physics, 139, 064306 (2013). © 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Is Part Of

VCU Physics Publications

Included in

Physics Commons