A theoretical measurement of the quantum transport through an optical molecular switch

The quantum transport through a dithienylcyclopentene wire is investigated using a Green function method combined with density functional theory. For both of its closed and open forms, the delocalized HOMOs of the molecule lie near the Fermi level of gold electrodes and the LUMOs are further apart from the Fermi level than the HOMOs. Consequently, the contribution of the HOMO to their electrical transmission is found to be dominant. The transmission through the open form is smaller than that through the closed one is ascribed to the larger energy difference between the HOMO and the Fermi level for the open form than that for the closed one.