A tutorial on the emerging nanotechnology devices

This paper provides an overview of the research on nanometer scale electronic switching devices. Such devices are likely to be used for building ultra-density integrated electronic computers of the future. We first describe the problems faced by the downscaling of FET devices and then discuss the emerging alternatives: 1) Carbon Nanotube transistors 2) Quantum effect and single-electron devices and 3) Molecular electronic devices. We discuss the basic operating principle of each type of device. Here mathematical details have been suppressed in favor of simpler understanding. The present state of the art for each new device is given, outlining the open problems for research. Finally, a possible time-line for their large-scale implementation is given.