Non-adiabatic effects of nuclear motion in quantum transport of electrons: A self-consistent Keldysh-Langevin study

Area of Science:

• Quantum Chemistry
• Molecular Electronics
• Condensed Matter Physics

Background:

• Molecular junctions are crucial for molecular electronics, but their behavior is complex.
• Understanding the interplay between nuclear motion and electronic transport is key.

Purpose of the Study:

• To model molecular junction geometry influenced by non-equilibrium electrons.
• To investigate current-induced nuclear dynamics and their feedback on electronic current.
• To analyze non-adiabatic corrections and their impact on transport properties.

Main Methods:

• Modeling nuclear degrees of freedom in a stochastic quantum environment.
• Using mean force, frictional force, and stochastic force for time-evolution.
• Employing non-equilibrium Green's functions and Keldysh-Kadanoff-Baym equations.
• Separating timescales in Wigner space.

Main Results:

• Non-adiabatic corrections are significant for non-equilibrium nuclear motion.
• Non-equilibrium descriptions yield higher conductance than equilibrium ones.
• Effective temperature effectively measures steady-state characteristics.
• Non-equilibrium dynamics can induce the Landauer blowtorch effect.

Conclusions:

• Non-equilibrium electron environments fundamentally alter molecular junction characteristics.
• The Landauer blowtorch effect emerges from non-equilibrium nuclear motion and temperature profiles.
• Accurate modeling requires considering non-adiabatic effects and nuclear dynamics feedback.