Eur. Phys. J. B (2013) 86: 180
https://doi.org/10.1140/epjb/e2013-30994-5

Regular Article

Spin waves transport across a ferrimagnetically ordered nanojunction of cobalt-gadolinium alloy between cobalt leads

¹ Institute for Molecules and Materials du Mans UMR 6283, University du Maine, 72085 Le Mans, France
² Graduate School of Sciences and Technology, Lebanese University, Hadath-Beirut, P.O. Box 5, Lebanon
³ Department of Physics, Texas A & M University, Education City, 23874 Doha, Qatar

^a e-mail: doried.ghader.etu@univ-lemans.fr

Received: 30 October 2012
Received in final form: 2 November 2012
Published online: 22 April 2013

Abstract

A model calculation is presented for the spin wave scattering and coherent transport at the ferrimagnetically ordered cobalt-gadolinium alloy nanojunction between cobalt leads. The structural model for the amorphous alloy nanojunction [Co_1/2Gd_1/2]₃ is considered as an ordered alloy hcp structure of three (0001) atomic planes between the leads. To analyze the spin dynamics and spin wave scattering at the nanojunction boundary, the phase field matching method (PFMT) is implemented over the ground state of the system, in the Heisenberg Hamiltonian representation. The coherent reflection and transmission probabilities of spin waves from the cobalt leads incident onto the nanojunction boundary are calculated, and numerical results are presented for the coherent SW transport across the nanojunction over the entire range of their frequencies. The results are especially valid in the interval between nanometric SW wavelengths greater than the nanojunction width and macroscopic wavelengths. They demonstrate in particular, the possibility of the resonance assisted maxima for the SW transmission spectra owing to the interactions between the incident spin waves and the localized spin resonances on the nanojunction. This effect is general and may be observed at different characteristic frequencies and corresponding incident angles.