Journal ArticleDOI
Validity of the Julliere model of spin-dependent tunneling
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TLDR
In this article, the authors consider spin-dependent tunneling between two ferromagnets separated by a simple step barrier, and examine four models for the magnetoconductance ratio of free electrons tunneling through a barrier.Abstract:
We consider spin-dependent tunneling between two ferromagnets separated by a simple step barrier, and examine four models for the magnetoconductance ratio $\ensuremath{\Delta}G/G:$ A model due to Julliere which characterizes the magnetoconductance solely in terms of the tunneling spin polarization, a model due to Slonczewski which provides an approximate expression for the magnetoconductance of free electrons tunneling through a barrier, the exact expression for the magnetoconductance of free electrons tunneling through a barrier, and the numerical calculation of the magnetoconductance of band electrons in iron tunneling through a barrier. We find that the Julliere model does not accurately describe the magnetoconductance of free electrons tunneling through a barrier. Although Slonczewski's model provides a good approximation to the exact expression for free electrons in the limit of thick barriers, we find that the tunneling of band electrons shows features that are not described well by any free electron picture and which reflect the details of the band structure of iron at the Fermi energy.read more
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Spintronics: Fundamentals and applications
TL;DR: Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems as discussed by the authors, where the primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport.
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Measuring the Spin Polarization of a Metal with a Superconducting Point Contact
R. J. Soulen,J. Byers,M. S. Osofsky,Boris Nadgorny,T. Ambrose,S. F. Cheng,P. R. Broussard,C. T. Tanaka,Janusz J. Nowak,Jagadeesh S. Moodera,A. Barry,J. M. D. Coey +11 more
TL;DR: A superconducting point contact is used to determine the spin polarization at the Fermi energy of several metals because the process of supercurrent conversion at a superconductor-metal interface (Andreev reflection) is limited by the minority spin population near the Fermani surface.
Journal ArticleDOI
Spin-dependent tunnelling in magnetic tunnel junctions
TL;DR: In this paper, the authors present an overview of spin-dependent tunnelling in magnetic tunnel junctions and discuss various factors that control the spin polarization and magnetoresistance in MTJ.
Journal ArticleDOI
Spin polarized tunneling in ferromagnetic junctions
TL;DR: In this paper, the authors review the experimental results and the current theoretical understanding of spin tunneling: its dependence on bias, temperature and barrier characteristics, and the influence of inelastic tunneling processes, metal at the interface and material properties on the JMR.
Journal ArticleDOI
Extrinsic magnetotransport phenomena in ferromagnetic oxides
TL;DR: In this article, a review of extrinsic magnetotransport effects in ferromagnetic oxides is presented, focusing on grain-boundary, tunnelling and domain-wall magnetoresistance.