• Rapid Communication

Theory of tunneling magnetoresistance of an epitaxial Fe/MgO/Fe(001) junction

J. Mathon and A. Umerski
Phys. Rev. B 63, 220403(R) – Published 10 May 2001
PDFExport Citation

Abstract

Calculation of the tunneling magnetoresistance (TMR) of an epitaxial Fe/MgO/Fe(001) junction is reported. The conductances of the junction in its ferromagnetic and antiferromagnetic configurations are determined without any approximations from the real-space Kubo formula using tight-binding bands fitted to an ab initio band structure of iron and MgO. The calculated optimistic TMR ratio is in excess of 1000% for an MgO barrier of 20 atomic planes and the spin polarization of the tunneling current is positive for all MgO thicknesses. It is also found that spin-dependent tunneling in an Fe/MgO/Fe(001) junction is not entirely determined by states at the Γ point (k=0) even for MgO thicknesses as large as 20 atomic planes. All these results are explained qualitatively in terms of the Fe majority- and minority-spin surface spectral densities and the complex MgO Fermi surface.

  • Received 21 December 2000

DOI:https://doi.org/10.1103/PhysRevB.63.220403

©2001 American Physical Society

Authors & Affiliations

J. Mathon and A. Umerski

  • Department of Mathematics, City University, London EC1V 0HB, United Kingdom

References (Subscription Required)

Click to Expand
Issue

Vol. 63, Iss. 22 — 1 June 2001

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×