The effect of thermal magnonic excitations on the electronic conductance of a magnetic nanowire

Abstract In this paper, we study the effect of thermal magnonic excitations on the electronic conductance of an anti-ferromagnetic nanowire which is coupled to two electrodes in the framework of equilibrium statistical mechanics. The electron-magnon scattering is assumed to be present only in the center part, not in the electrodes. For each magnonic mode of the chain, we calculate a Green’s function and the corresponding mode-dependent transmission coefficient via the linear response theory. Then, the total electronic transmission through the system is obtained by the summation of the mode-dependent ones. We examine the influence of magnonic waves on three different configurations for the center wire including uniform, alternative on-site (AB) and polyacetylene like (PA-like) chain. Two types of nonmagnetic and ferromagnetic structures are chosen for the left and right leads. The results show that the effect of magnonic excitations on the electronic conductance of the considered systems is important at high temperatures. Especially, the electron tunneling conductance is improved in the presence of magnonic excitations in the PA-like and AB nanowires in contrast to the uniform one. While for all configurations, the conductance decreases in the resonance region by increasing the magnonic effects. Finally, we discuss the spin polarization and we show that the effect of thermal magnonic excitations is more observable in AB with respect to PA-like and in PA-like with respect to the uniform configuration of the center wire.