Spin-polarized Tunneling in Hybrid Metal-Semiconductor Magnetic Tunnel Junctions
Abstract
We demonstrate efficient spin-polarized tunneling between a ferromagnetic metal and a ferromagnetic semiconductor with highly mismatched conductivities. This is indicated by a large tunneling magnetoresistance (up to 30%) at low temperatures in epitaxial magnetic tunnel junctions composed of a ferromagnetic metal (MnAs) and a ferromagnetic semiconductor (GaMnAs) separated by a nonmagnetic semiconductor (AlAs). Analysis of the current-voltage characteristics yields detailed information about the asymmetric tunnel barrier. The low temperature conductance-voltage characteristics show a zero bias anomaly and a V^1/2 dependence of the conductance, indicating a correlation gap in the density of states of GaMnAs. These experiments suggest that MnAs/AlAs heterostructures offer well characterized tunnel junctions for high efficiency spin injection into GaAs.
Keywords
Cite
@article{arxiv.cond-mat/0207178,
title = {Spin-polarized Tunneling in Hybrid Metal-Semiconductor Magnetic Tunnel Junctions},
author = {S. H. Chun and S. J. Potashnik and K. C. Ku and P. Schiffer and N. Samarth},
journal= {arXiv preprint arXiv:cond-mat/0207178},
year = {2009}
}
Comments
14 pages, submitted to Phys. Rev. B