Spin-dependent scattering of electron wave on multi-barrier non collinear system

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

Keywords: spin dependent transport, resonant tunneling, valve effect, spin polarization, magnetic nanostructure, noncolliearity, windows of polarization, internal magnetic field, single-domain system

Summary:

Spin-dependent scattering of electron wave on multi-barrier noncollinear system aA.S. Sahakyan, aA.V. Poghosyan, a R.M. Movsesyan, bA.N. Kocharian a National Polytechnic University of Armenia, Yerevan, Armenia bDepartment of Physics, California State University, Los Angeles, USA A spin-dependent transmission of scattering electrons is considered on a film consisting of alternating magnetic and nonmagnetic nanolayers. It is assumed that the potential relief of the system consists of magnetized potential barriers separated by non-magnetic quantum wells. The induction vectors of the internal magnetic fields of the barriers are located in the planes of the nanolayers and form the angles with some selected (preferred) direction, i.e. actually (in general ) are non-collinear. The spin scattering of a non-polarized electron wave on this system is considered, and the dependences of the transmission coefficient and polarization degree of the transmitted wave on the abovementioned noncollinear degrees of freedom and the momentum variable parameterizing the energy of elastic scattering are investigated. It is shown that the transport characteristics are periodic functions of the degrees of freedom, i.e. corresponding angles. The amplitude of their oscillations, for example, with respect to the variable essentially depends on the fixed value of angle at the second layer. As electron momentum increases the oscillations decrease significantly; at the same time, the transmission coefficient increases and asymptotically approaches to one, while the spin polarization monotonously decreases approaching zero. The behavior of transport characteristics of a system as a functions of corresponding angles are investigated under conditions of partial resonance (i.e., studies of k-values at which the transmission coefficient of the corresponding collinear system becomes one).