Motor effect in electron transport through a molecular junction with torsional vibrations

Abstract

We propose a model for a molecular junction with internal anharmonic torsional vibrations interacting with an electric current. The Wangsness-Bloch-Redfield master equation approach is used to determine the stationary reduced density matrix of the molecule. The dependence of the current, excitation energy and angular momentum of the junction on the applied voltage is studied. Negative differential conductance is observed in the current-voltage characteristics. It is shown that a model with vibrationally dependent coupling to the electrodes, asymmetric with respect to the interchanging of electrodes, leads to a strong correlation between the applied voltage and the angular momentum of the junction. The model thus works as a molecular motor, with the angular momentum controlled by the size and sign of the voltage.

References in corpus (11)

• Dependence of Single Molecule Junction Conductance on Molecular Conformation
• Molecular Transport Junctions: Vibrational Effects
• Franck-Condon blockade and giant Fano factors in transport through single molecules
• Vibrational sidebands and dissipative tunneling in molecular transistors
• Tunneling through molecules and quantum dots: master-equation approaches
• Kinetic Equations for Transport Through Single-Molecule Transistors
• Length-dependent conductance and thermopower in single-molecule junctions of dithiolated oligophenylene derivatives
• Cooling mechanisms in molecular conduction junctions
• Cooling carbon nanotubes to the phononic ground state with constant electron current
• Vibrational effects in laser driven molecular wires
• A self-consistent quantum master equation approach to molecular transport

Cited by in corpus (11)

• Bias-Controlled Selective Excitation of Vibrational Modes in Molecular Junctions: A Route Towards Mode-Selective Chemistry
• Current-induced forces and hot-spots in biased nano-junctions
• Current Noise in Single-Molecule Junctions Induced by Electronic-Vibrational Coupling
• Cooling by heating in nonequilibrium nanosystems
• Edge-plasmon assisted electro-optical modulator
• Vibrationally dependent electron-electron interactions in resonant electron transport through single-molecule junctions
• Effects of vibrational anharmonicity on molecular electronic conduction and thermoelectric efficiency
• Controlling the conductance of molecular junctions using proton transfer reactions: A theoretical model study
• A physically realizable molecular motor driven by the Landauer blowtorch effect
• An ignition key for atomic-scale engines
• Surface phonon induced rotational dissipation for nanoscale solid-state gears