Magnetic Heterostructures with Tunable Spin-dependent Transport Properties

A.S. Sahakyan, A.V. Poghosyan, R.M. Movsesyan, A.N. Kocharian
California State University, Los Angeles,
United States

Keywords: magnetic nanolayers, nano heterostructure, magnetic defect, spin-dependent scattering, transfer matrix

Summary:

The transport properties in magnetic films consisting of alternating magnetic nanolayers separated by nonmagnetic quantum wells are studied for a definite finite number of (N) magnetic barriers consisting of two branches of ferromagnetically ordered structures. The magnetic ordering of the magnetizations in each of the branches provides conditions for a resonant tunneling, where the presence of “non-coplanar defect” inclusions destroys this resonant transmission leading to two-channel electron scattering with and without a spin flip. We find that the degree of polarization of the transmitted wave as a function of scattering energy can have a resonant behavior for certain values of the coordinates of a non-coplanar defect and is due to the quantum interference of the incident on the defect and reflected waves from it. This is ultimately due to the possibility of resonant tunneling in each of the branches of the considered structure. In addition, the degree of spin polarization of the transmitted wave is very insensitive to the variation of transverse magnetization component to the surface of the noncoplanar defect. In principle, it is also possible to switch off the interference of an electron wave once the transmission coefficient reaches its minimum value.