Direct writing of in-plane-gated nanostructures by focused laser beam-induced doping

The fabrication technique of local doping with a focused laser beam is employed to fabricate electronic nanostructures. Zn-doped regions are used to fabricate in-plane electron channels in a high mobility GaAs/AlGaAs heterostructure. The operation of different devices, like quantum point contacts, single electron transistors or Aharonov-Bohm rings, is demonstrated. The coplanar gate geometry improves the performance of the devices in charge sensing applications.