MAGNETIC-FIELD-INDUCED RESONANT-TUNNELING IN PARALLEL 2-DIMENSIONAL SYSTEMS

The magnetoresistance at 4.2 K of two spatially remote two-dimensional electron gases is investigated. The magnetic field B is applied paral lel to the planes of the two-dimensional electron gases (2DEG's). Tunn eling between them occurs above a critical held B,. In a configuration where the current I is perpendicular to B, a resistance resonance is observed at B-c, which is absent when I is parallel to B. This resista nce resonance is due to a large difference in the mobilities of the tw o 2DEG's. A model calculation based on the Boltzmann equation and the symmetry properties of the electron subband dispersion curves reproduc es the observed phenomena.