Electronic transport through molecular junctions with nonrigid molecule-leads coupling

Area of Science:

• Molecular Electronics
• Quantum Transport
• Computational Chemistry

Background:

• The Landauer-type formulation describes current in molecular junctions.
• Electronic-nuclear coupling is crucial for understanding molecular behavior.
• Previous models focused on internal molecular coupling.

Purpose of the Study:

• Generalize the Landauer-type formulation to include external electronic-nuclear coupling.
• Investigate the impact of molecule-leads coupling dependence on nuclear coordinates.
• Analyze the effects of vibrating contacts on current transport.

Main Methods:

• Generalized Landauer-type formulation.
• Projection operator techniques.
• Numerical simulations of a conductor with vibrating contacts.

Main Results:

• External electronic-nuclear coupling can be incorporated without extending the molecular subspace.
• Contact vibrations introduce inelastic contributions to the current.
• Characteristic features appear in the I-V curve and its derivatives due to contact vibrations.

Conclusions:

• The generalized model accurately captures the effects of external electronic-nuclear coupling.
• Vibrating contacts mimic effects of internal molecular coupling on current.
• This work provides a more comprehensive understanding of charge transport in molecular junctions.