ELECTRONIC TRANSPORT IN SMALL STRONGLY LOCALIZED STRUCTURES

We review some recent results on the low-temperature transport properties (T less than 4 K) of very small silicon metal-oxide field-effect transistors in the insulating regime of conduction. Our devices are lithographically patterned to have widths as small as 0. 05 mu m and lengths as short as 0. 06 mu m. These small transistors exhibit new and unexpected sample-specific fluctuation behavior in the gate voltage, temperature, and magnetic field dependence of the conductance. We discuss both resonant tunneling and Mott variable-range hopping, the two main transport mechanisms in these devices at low temperature.