Ballistic InAs nanowire transistors.

Ballistic transport of electrons at room temperature in top-gated InAs nanowire (NW) transistors is experimentally observed and theoretically examined. From length dependent studies, the low-field mean free path is directly extracted as similar to 150 nm. The mean free path is found to be independent of temperature due to the dominant role of surface roughness scattering. The mean free path was also theoretically assessed by a method that combines Fermi's golden rule and a numerical Schrodinger-Poisson simulation to determine the surface scattering potential with the theoretical calculations being consistent with experiments. Near ballistic transport (similar to 80% of the ballistic limit) is demonstrated experimentally for transistors with a channel length of similar to 60 nm, owing to the long mean free path of electrons in InAs NWs.