Conductivity switching of two benzene rings under electric field*

We study the electron transport and switching of S-C$_6$H$_3$F(CH3)-C$_6$H$_3$(CH3)F-S molecule sandwiched between two Au(111) electrodes using plane wave quantum transport calculation method described in [1-2]. A nonlocal pseudopotential method is used to describe the system, and scattering states are calculated. We found that under zero external electric field, the two rings have a perpendicular configuration, while under strong external electric field they change into a planar configuration. As a result, the quantum conductivity of the system will increase for more than ten times. We propose to use this as a molecular switch, serving the function of a transistor.\\[4pt] [1] Lin-Wang Wang, PRB \textbf{72}, 045417 (2005)\\[0pt] [2] A. Garc\'{\i}a-Lekue and Lin-Wang Wang, PRB \textbf{74}, 245404 (2006)