Current-induced rotations of molecular gears
Résumé
Downsizing of devices opens the question of how to tune not only their electronic properties, but also
of how to influence ‘mechanical’ degrees of freedom such as translational and rotational motions.
Experimentally, this has been meanwhile demonstrated by manipulating individual molecules with
e.g. current pulses from a Scanning Tunneling Microscope tip. Here, we propose a rotational version
of the well-known Anderson-Holstein model to address the coupling between collective rotational
variables and the molecular electronic system with the goal of exploring conditions for unidirectional
rotation. Our approach is based on a quantum–classical description leading to effective Langevin
equations for the mechanical degrees of freedom of the molecular rotor. By introducing a timedependent
gate to mimic the influence of current pulses on the molecule, we show that unidirectional
rotations can be achieved by fine tuning the time-dependence of the gate as well as by changing the
relative position of the potential energy surfaces involved in the rotational process
Domaines
Physique [physics]
Origine : Fichiers éditeurs autorisés sur une archive ouverte
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