Conductance of Small Molecular Junctions

Abstract

A new method of fabricating small metal-molecule-metal junctions is developed, approaching the single-molecule limit. The conductance of different conjugated molecules in a broad temperature, source-drain, and gate voltage regime is reported. At low temperature, all investigated molecules display sharp conductance steps periodic in source-drain voltage. The position of these steps can be controlled by a gate potential. The spacing corresponds to the energy of the lowest molecular vibrations. These results show that the low-bias conductance of molecules is dominated by resonant tunneling through coupled electronic and vibration levels.

Self-consistent theory of molecular switching

“…[15][16][17][18][19][20][21] This corresponds to the bare tunnel broadening ប⌫ of molecular electronic levels smaller than the energy required to excite one oscillator quantum ͑phonon͒ ប 0 . The single-electron effects play a crucial role in this case.…”

Transport Through a Driven Three-Site System

“…The conventional setup of such a transistor requires a gate in order to trigger via the gate voltage the current from the source to the drain which correspond to the lead contacts of the molecular system. In fact, the implementation of a single gate electrode which creates a sufficiently strong field at the molecule is a demanding task [2,10,11]. Instead of using the static fields of a gate electrode, oscillating external fields or an oscillating gate voltage might be a convenient alternative to control the electrical current according to a molecular field-effect transistor.…”

CMOL: Second life for silicon?

“…(Their main components, molecular single-electron transistors, have already been demonstrated by several research groups [12][13][14][15][16]. )…”