Resonant tunneling through states in the barrier of a magnetic tunnel junction has been analyzed theoretically for the case of a spin-polarized density of barrier states. It is shown that for highly spin-polarized barrier states, the magnetoresistance due to resonant tunneling is enhanced compared to the magnetoresistance due to direct tunneling between the ferromagnetic electrodes. Moreover, i...

Tunneling through time-dependent potentials is of relevance to a number of physical problems. Using a WKB analysis Azbel' has recently studied the effects of a nonharmonic time-dependent perturbation embedded in an opaque potential barrier. He suggests the existence of three different regimes for transmission in such systems: direct tunneling, activation assisted tunneling, and elevator resonan...