Tunnelling and transfer between 1D and 2D electrons in adjusted quantum wells with thin barrier

By the technique of in situ focused ion-beam implantation in an underlying doping layer followed by molecular beam epitaxy overgrowth of a double quantum-well we have fabricated adjusted one-dimensional and two-dimensional electrons with very thin barrier between them. Each of the electron systems could be contacted separately. The tunnelling resistance between electron layers increases at high in-plane magnetic fields. With magnetic fields perpendicular to the wire we can investigate the coupling of lower one-dimensional subband while in the parallel direction higher subband states hybridise. In the first case, we observed clear resonance in the tunnelling and electron transfer.