Theory of Tunneling and its Dependence on a Longitudinal Magnetic Field

A theory of interband tunneling due to a constant electric field is presented which is free of certain objections to previous theories. It is shown that the expression for the Zener current has new terms oscillatory in the electric field, which reflect the Stark quantization of the longitudinal motion of the electron. It is pointed out that for sufficiently small electric fields, the tunneling probability itself is an oscillatory function of the electric field. The effect of a longitudinal magnetic field on the tunneling is calculated for a class of substances. The tunneling in InSb in a magnetic field is considered in detail. Effects of spin-orbit interaction and nonparabolicity of energy bands are taken into account.