Magnetic-field-induced tunneling and minigap transport in double quantum wells

We review recent theoretical and experimental results on low-temperature tunneling and in-plane transport properties in double quantum wells (DQWs) in an in-plane magnetic field B_ǁ. These properties arise from the combined effect of B _ǁ-induced relative displacement of the wave vectors in the two QWs and the interwell tunneling. In weakly coupled DQWs, the tunneling conductance has two sharp maxima as a function of B _ǁ. In strongly coupled DQWs, a partial minigap is formed due to the anticrossing of the two QW dispersion curves, yielding sharp B _ǁ-dependent structures in the density of states and in-plane transport properties. Excellent agreement is obtained between the theory and the data from GaAs/AlGaAs DQWs.