Wessely, O.; Umerski, A. and Mathon, J.
(2009).
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| DOI (Digital Object Identifier) Link: | http://dx.doi.org/doi:10.1103/PhysRevB.80.014419 |
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| Google Scholar: | Look up in Google Scholar |
Abstract
Two alternative current-induced switching geometries, in which the current flows parallel to the magnet/nonmagnet interface, are investigated theoretically using the nonequilibrium Keldysh theory. In the first geometry, the current is perpendicular to the polarizing magnet/nonmagnet interface but parallel to the nonmagnet/switching magnet interface (CPIP). In the second geometry, the current is parallel to both polarizing magnet/nonmagnet and nonmagnet/switching magnet interfaces (CIP). Calculations for a single-orbital tight-binding model indicate that the spin current flowing parallel to the switching magnet/nonmagnet interface can be absorbed by a lateral switching magnet as efficiently as in the traditional current-perpendicular-to-plane (CPP) geometry. The results of the model calculations are shown to be valid also for experimentally relevant Co/Cu CPIP system described by fully realistic tight-binding bands fitted to an ab initio band structure. It is shown that almost complete absorption of the incident spin current by a lateral switching magnet occurs when the lateral dimensions of the switching magnet are of the order of 50–100 interatomic distances, i.e., about 20 nm and its height as small as a few atomic planes. It is also demonstrated that strong spin current absorption in the CPIP/CIP geometry is not spoiled by the presence of a rough interface between the switching magnet and nonmagnetic spacer. Polarization achieved using a lateral magnet in the CIP geometry is found to be about 25% of that in the traditional CPP geometry. The present CPIP calculations of the spin-transfer torque are also relevant to the so-called pure-spin-current-induced magnetization switching that had been recently observed.
| Item Type: | Journal Article |
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| Copyright Holders: | 2009 The American Physical Society |
| ISSN: | 1098-0121 |
| Funders: | UK Engineering and Physical Sciences Research Council |
| Keywords: | interface magnetism; magnetic switching; spin polarised transport; tight-binding calculations |
| Academic Unit/Department: | Mathematics, Computing and Technology > Mathematics and Statistics |
| Item ID: | 18022 |
| Depositing User: | Andrey Umerski |
| Date Deposited: | 27 Aug 2009 13:28 |
| Last Modified: | 12 Dec 2012 19:45 |
| URI: | http://oro.open.ac.uk/id/eprint/18022 |
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