Eur. Phys. J. B (2012) 85: 163
https://doi.org/10.1140/epjb/e2012-30056-8

Regular Article

Effects of dephasing on the spin-dependent currents and noise power in a molecular junction

¹ Department of Physics, Science and Research Branch, Islamic Azad University, 14665-678 Tehran, Iran
² School of Physics, Damghan University, Damghan, Iran

^a e-mail: a.ahmadifouladi@iausari.ac.ir

Received: 22 January 2012
Received in final form: 8 March 2012
Published online: 24 May 2012

Abstract

The role of dephasing reservoirs on the spin-dependent transport through a polythiophene (PT) molecule sandwiched between ferromagnetic 3-dimensional electrodes as a FM/PT/FM junction is numerically investigated. Our calculations are performed based on a tight-binding model and a generalized Green’s function method in the well-known Landauer-Büttiker formalism. We investigate the influence of dephasing reservoirs on the spin dependent currents, noise power, Fano factor and tunnel magnetoresistance (TMR) of the junction. Our results illustrate that the presence of dephasing reservoirs give rise to increase the currents and noise power due to reduced destructive interference resulting from the Büttiker probes. We found the significant change in the Fano factor and TMR of the FM/PT/FM junction in the presence of dephasing reservoirs. Furthermore, we explore the influence of the electrode/molecule coupling strength on the transport properties of the FM/PT/FM junction. It is shown that the electrode/molecule coupling strength may control the spin-dependent transport properties and so it is a significant parameter for designing of the efficient molecular spintronic devices.