Transient magnetic tunneling mediated by a molecular bridge in the junction region

¹ Institute of Physics ASCR, Na Slovance 2, 182 21 Praha 8, Czech Republic
² Dept. of Condensed Matter Physics, Charles University, 121 16 Praha 2, Czech Republic

^a e-mail: kalvova@fzu.cz

Published online: 3 July 2014

Abstract

This paper extends our recent theoretical study of transient currents in molecular bridge junctions [1] to magnetic tunneling. Presently, we calculate the excess magnetic tunneling through the molecular bridge shunting the junction. The system is represented by two ferromagnetic electrodes bridged by a molecular size island with one electronic level and a local Hubbard type correlation. The island is linked with the electrodes by tunneling junctions whose coupling strength is assumed to undergo rapid changes affecting the connectivity of the system. We employ the non-equilibrium Green’s functions. The numerical solution is obtained solving the real-time Dyson equation in the integro-differential form self-consistently. The switching events controlling the junctions give rise to transient changes of magnetisation of the island. They strongly depend on the static galvanic bias between the electrodes, mutual alignment of their magnetisation and on the time scale of the switching.