Electrical probe for mechanical vibrations in suspended carbon nanotubes

The transport properties of a suspended carbon nanotube probed by means of a scanning tunnel microscope (STM) tip are investigated. A microscopic theory of the coupling between electrons and mechanical vibrations is developed. It predicts a position-dependent coupling constant, sizable only in the region where the vibron is located. This fact has profound consequences on the transport properties, which allow to extract information on the location and size of the vibrating portions of the nanotube.