Spin-dependent electronic transport of a lengthy ladder-like magnetic nanoribbon

We propose a theoretical method based on Green's function technique within the tight-binding approach to consider the spin-dependent electronic conductance of a lengthy ladder-like magnetic nanoribbon. A part of this nanoribbon which is located in the middle is presumed to be different from other ideal parts. We utilize a unitary transformation to separate conductance modes in the ideal parts in order to insert them effectively by fully analytical self-energies in the middle part of Green's function. Finally, the model is examined to perform numerical calculation for some proposed configurations. The model can aid our understanding and design of the spin-filtering electronic narrow nanoribbons.