Coherent light-driven electron transport through polycyclic aromatic hydrocarbon: laser frequency, field intensity, and polarization angle dependence

Laser frequency, field intensity, and polarization angle dependence of photon assisted tunneling in molecular junctions.

Theoretical Design of an Aromatic Hydrocarbon Rotor Driven by a Circularly Polarized Electric Field

An aromatic hydrocarbon rotor without functional groups is theoretically designed. Such a molecular rotor is free from long-range electrostatic interactions. Induced dipole interactions are the rotor-driving forces under a nonresonant excitation condition. As an example, a molecular rotor with a condensed aromatic ring, a pentacene moiety mounted on a phenyl-acetylene axle that is driven by a circularly polarized electric field is considered. Results of simulations of the quantum dynamics of a rotor that take into account short-range rotor-bath interactions are presented by numerically solving the density matrix equations of the rotational motions.

Synthetic molecular motors and mechanical machines

The widespread use of controlled molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular systems, which by and large rely upon electronic and chemical effects to carry out their functions, and the machines of the macroscopic world, which utilize the synchronized movements of smaller parts to perform specific tasks. This is a scientific area of great contemporary interest and extraordinary recent growth, yet the notion of molecular-level machines dates back to a time when the ideas surrounding the statistical nature of matter and the laws of thermodynamics were first being formulated. Here we outline the exciting successes in taming molecular-level movement thus far, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion. We also highlight some of the issues and challenges that still need to be overcome.