Current-voltage relation for thin tunnel barriers: Parabolic barrier model

We derive a simple analytic result for the current-voltage curve for tunneling of electrons through a thin uniform insulating layer modeled by a parabolic barrier. Our model, which goes beyond the Wentzel-Kramers-Brillouin approximation, is applicable also in the limit of highly transparant barriers subject to high voltages, and thus provides a more realistic description for this situation compared to the widely used rectangular barrier model. (C) 2004 American Institute of Physics.