Effects of Molecular Conformation on the Spin-Dependent Transport Through the FM/Biphenyl/FM Junction

Effects of conformation on the spin-dependent transport in a molecular spin-valve, as FM/biphenyl/FM model junction, in which a biphenyl molecule attached to ferromagnetic (FM) electrodes are numerically investigated. The work is based on a tight-binding Hamiltonian model within the framework of a generalized Green's function method and relies on the Landauer-Buttiker formalism as the basis for studying the spin-dependent transport properties of this system. We have found that transport characteristics, including the spin-dependent transmission function, current and tunnel magnetoresistance (TMR) are strongly influenced by the variation of twist angle between two phenyl rings. It is shown that the twist angle can alter the sign of the TMR from a positive to a negative value. We think that the results of the present report could be useful for designing the future molecular spintronic devices.