Ab Initio Theory of Perpendicular Transport in Metallic Magnetic Multilayers
The current-perpendicular-to-plane (CPP) magnetoconductance of a sample sandwiched by two ideal non-magnetic leads is described at an ab initio level. The socalled ‘active’ part of the system is a trilayer consisting of two magnetic slabs of finite thickness separated by a non-magnetic spacer. We use a transmission matrix formulation of the conductance based on surface Green functions as formulated by means of the tight-binding linear muffin-tin orbital method. An equivalent and computationally more efficient formulation of the problem based on reflection matrices is also presented. The formalism is extended to the case of lateral supercells with random arrangements of atoms which in turn allows to deal with ballistic and diffusive transport on equal footing. Applications refer to fcc-based Co/Cu/Co(001) trilayers.
KeywordsGiant Magnetoresistance Coherent Potential Approximation Space Thickness Empty Symbol Spacer Layer Thickness
Unable to display preview. Download preview PDF.
- W.H. Butler, X.-G. Zhang, D.M.C. Nicholson, and J.M. Mac Laren, First-Principles Calculations of Electrical-Conductivity and Giant Magnetoresistance of Co-Vertical-Bar-Cu-Vertical-Bar-Co Spin Valves Phys. Rev. B 52, 13399 (1995).Google Scholar
- S. Datta, Electronic Transport in Mesoscopic Systems (Cambridge University Press, Cambridge, 1995).Google Scholar
- J. Cerdá, M.A. Van Hove, P. Sautet, and M. Salmeron, Efficient method for the simulation of STM images. I. Generalized Green-function formalism Phys. Rev. B 56, 15885 (1997).Google Scholar
- S. Sanvito, C.J. Lambert, J.H. Jefferson, and A.M. Bratkovsky, General Green’s-function formalism for transport calculations with spd Hamiltonians and giant magnetoresistance in Co- and Ni-based magnetic multilayers Phys. Rev. B 59, 11936 (1999).Google Scholar
- B.L. Gyorffy and G.M. Stocks, in Electrons in Disordered Metals and at Metallic Surfaces, eds. P. Phariseau, B.L. Gyorffy, and L. Scheire (NATO ASI Series, Plenum Press, New York, 1979).Google Scholar