Electric-pulse-induced resistance switching observed in ZnO nanotube point contact system

Based on the scanning tunneling microscopy (STM) techniques, we successfully completed a novel two-terminal electron transport measurement on individual zinc oxide (ZnO) nanotube. This method enabled us to set one of these two metal-semiconductor contacts as a point contact. In this system, we found ZnO nanotube exhibit reproducible polarized memory effect and electrical-pulse-induced resistance switching effect. We suggested a phenomenological model to explain the observed effects.