NEW SIZE EFFECTS IN THE CONDUCTIVITY OF METAL-INSULATOR-METAL TUNNEL-JUNCTIONS

A simple theory that makes it possible to calculate the characteristic s of metal-insulator-thin metal film tunnel junctions is developed. Al ong with the well-known oscillations in the voltage dependence sigma(V ) of tunneling conductance due to commensurate states, it predicts a n umber of new effects. For example, even in the case of a symmetric tun nel junction formed by the identical materials with a rectangular pote ntial barrier, the sigma(V) curve displays a noticeable asymmetry. The branch of the sigma(V) curve corresponding to tunneling to the thinfi lm electrode contains a structure consisting of conductance dips. (C) 1998 American Institute of Physics. [S1063-777X(98)00907-4].