Theory of nanotube opto-electromechanical device

Theory of a novel carbon nanotube opto-electronic switch is presented. Current control is realized at the molecular level by applying field of an atomic charge or atomic dipole across the nanotube channel, which can work as a local gate. In the case of a unit (1 e) point charge, close to the surface, a scattering potential strength is /spl sim/2 eV if neglecting the screening. Thus, the screened potential has to be used and it is /spl sim/0.1 eV for a SWNT with typical parameters. In case of the dipole scatterer, the potential is approximately 10 times weaker. The change of the dipole orientation with respect to the channel axis modulates the potential shape from a single barrier/well to a coupled triangular barrier and well. A possibility for creating a light-controlled electronic device is discussed.