Decoherence and Dephasing in Molecular Electronic Devices

This paper presents theoretical studies of the effect of decoherence on nonlinear electron transport that affect the current-voltage (I-V) characteristics as well as the power dissipated in the molecular electronic devices. The calculations are performed using the non-equilibrium Green functions (NEGF) formalism applying the Hückel concept to linear atomic chains weakly connected to terminals (electrodes). Those interconnected molecules are examined by making use of the wide-band approximation. The charging effects are modeled using the self-consistent potential, while the dephasing effect is examined by the use of complex potential. It is shown that for higher voltages the molecular junction may be unstable due to incoherent conduction process, while the magnitude of the current flowing through the junction decreases exponentially with increasing the values of dephasing potential.