Transient Current Behavior through Molecular Bridge Systems; Effects of Intra-Molecule Current on Quantum Relaxation and Oscillation

Abstract

Transient current behavior through two-site molecular bridge systems is studied using density-matrix calculations in order to clarify the multi-site effects in molecule. It is shown that, as increasing the number of energy-level sites in molecule, the relaxation speed becomes slow and the period of current oscillation increases reflecting the change of electronic states in molecule. Moreover, we found that the intra-molecule quantum electron motion often induces a new oscillation and largely modulates the transient current behavior. This motion is also expected seen as a spike-like vibration in steady-state current when a molecule changes its structure such as by the adsorption and desorption of another molecule. [DOI: 10.1380/ejssnt.2009.606]