TUNNEL MAGNETORESISTANCE OF AN ORGANIC MOLECULE JUNCTION

Coherent spin-dependent electronic transport is investigated in a molecular junction made of organic molecule (linear chain of benzene rings) attached to two the semi-infinite ferromagnetic (FM) electrodes with finite cross sections (Fig. 1). The work is based on the tight-binding Hamiltonian model and within the framework of a non-equilibrium Green’s function (NEGF) technique. It is shown that tunnel magnetoresistance (TMR) of molecular junction can be large (over 60 %) by adjusting the related parameters, and depends on: (i) the applied voltages and (ii) the number of benzene rings. Fig. 1. A schematic representation of the FM/organic molecule/FM molecular junction in two configurations Parallel (P) and Anti-Parallel (AP) magnetization. Hamiltonian for the system of two ferromagnetic electrodes joined by an organic molecule is proposed in the following form: Hamiltonian for the molecular (HM) is:,.)c.hcct(ccH,