General Theory of Tunneling in Oxide Diodes

The well-known theory of tunneling in oxide diodes is the tunneling-Hamiltonian method, but this cannot describe processes happening in the oxide layer. Some new experiments necessitate the treatment of the electrons in the barrier as well. The author has elaborated a method using Green's functions to describe the whole phenomenon in an iterative procedure. The starting point is the treatment of two other problems where the metal on the left or right side of the barrier is replaced by an insulator. The current density in the barrier has been derived for normal and superconducting junctions. The phenomenon in a magnetic field has been treated using the microscopic theory, avoiding phenomenological considerations. The applicability of the tunneling Hamiltonian has been investigated; by its use the total current may be calculated. This method has proved to be very suitable for the problem of the anomalous tunneling between two normal metals with paramagnetic impurities in the barrier.