Wave functions and Fermi surfaces of strongly coupled two-dimensional electron gases investigated by in-plane magnetoresistance

We have studied the in-plane magnetoresistance of coupled double-quantum-well structures, in which each well has a different mobility and where the values of carrier concentration can be varied independently. Resistance resonances, observed at zero magnetic field, were suppressed with an in-plane magnetic field of 1 T, provided the field was perpendicular to the current. The magnetoresistance showed structure which changed systematically with front-gate and back-gate voltages, and was due to the deformation of both wave functions and Fermi surfaces in the in-plane magnetic field.