Spin-dependent trapping of electrons at spinterfaces
Abstract
Hybrid ferromagnetic metal/organic interfaces--also known as spinterfaces--can exhibit highly efficient spin-filtering properties and therefore present a promising class of materials for the future development of new spintronic devices. Advancing the field depends critically on elucidating the fundamental microscopic processes that eventually determine the spin-filtering properties in such hybrid structures. Here, we study the femtosecond spin dynamics at the prototypical interface between cobalt and the metalorganic complex tris(8-hydroxyquinolinato)aluminium. To disentangle the microscopic origin of spin filtering, we optically generate a transient spin polarization in a well-defined hybrid interface state that we follow with a spin-resolved real-time pump-probe two-photon photoemission experiment. We find that the electrons are trapped at the interface in a spin-dependent manner for a surprisingly long time of the order of 0.5-1ps. We conclude that ferromagnetic metal/organic interfaces act as spin filters because electrons are trapped in hybrid interface states by spin-dependent confining potentials.
- Publication:
-
Nature Physics
- Pub Date:
- April 2013
- DOI:
- 10.1038/nphys2548
- Bibcode:
- 2013NatPh...9..242S