Cotunneling model for current-induced events in molecular wires

Area of Science:

• Molecular electronics
• Quantum transport phenomena
• Surface science

Background:

• Standard Landauer picture is insufficient for molecular transport involving electronic state transitions.
• Coherent second-order processes, or cotunneling, are crucial at low temperatures.

Purpose of the Study:

• To present a theoretical model for cotunneling in molecular wires.
• To explain phenomena not captured by the Landauer model.
• To investigate STM-induced acetylene dissociation.

Main Methods:

• Development of a cotunneling model for molecular wires.
• Theoretical analysis of coherent second-order quantum processes.
• Application of the model to STM-induced acetylene dissociation.

Main Results:

• The cotunneling model accurately describes electronic transitions in molecular wires.
• The model explains the high voltage threshold observed in STM-induced acetylene dissociation.
• Cotunneling provides a more comprehensive description of molecular transport.

Conclusions:

• Cotunneling is a key mechanism in molecular transport junctions.
• The presented model offers a powerful tool for understanding molecular wire behavior.
• This work elucidates the mechanism behind STM-induced acetylene dissociation.