Long-range charge transport in homogeneous and alternating-rigidity chains.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Physical Chemistry

Background:

• Long-range charge transport in molecular systems is crucial for molecular electronics.
• Understanding the influence of intrinsic electronic properties and environmental factors is complex.

Purpose of the Study:

• Investigate the interplay of electronic structure and thermal effects on charge transport in molecular chains.
• Identify design principles for efficient long-range charge transport in molecular systems.

Main Methods:

• Utilized a tight-binding Hamiltonian to model molecular electronic structure.
• Incorporated thermal effects (decoherence, inelastic scattering) via the Landauer-Büttiker probe method.
• Simulated modular polymers with varying rigidity to explore transport behavior.

Main Results:

• Observed a crossover from coherent to thermally-assisted conduction in short chains, with thermal effects enhancing current.
• Identified unconventional, non-monotonic transport behavior with increasing chain length under specific coupling conditions.
• Found that thermal effects suppress conductance in long chains below the coherent-ballistic limit.
• Demonstrated that electrical resistance averages out, showing insensitivity to patterned environmental structuring despite affecting charge correlations.

Conclusions:

• Efficient long-range charge transport necessitates careful engineering of both internal electronic parameters and external environmental conditions.
• Minimal models for unconventional and effective molecular transport require consideration of both electronic coupling and environmental interactions.