Electron transport properties through a benzene-type quantum dots molecular system

Abstract

A benzene-type quantum dots molecular model is designed, and the conductance and time-average current through the system are obtained using the Green's function. The results show that one single resonance peak changes to three resonance peaks with increasing the inter-dot coupling strength. The intensities of the twin peaks in the conductance spectrum are sensitive to the dot-lead coupling strength. An anti-resonance band emerges in the conductance spectrum as the dot-lead coupling strength is strong enough. When an external magnetic field is introduced, the original three conductance resonance peaks evolves into six resonance peaks and meanwhile two anti-resonance bands occur. The widths of the new anti-resonance bands can be tuned by adjusting the magnetic flux. Moreover, a photon-assisted tunneling phenomenon can be observed when the system is irradiated by a time-dependent external field. These results provide insights into the design and development of efficient molecular electronics.