Fabrication of parallel quantum point contacts with submicron airbridges

An airbridge technique was developed and subsequently employed to fabricate mesoscopic devices, such as parallel quantum point contacts. The airbridge technique mainly involves two different electron sensitive polymers, polymethylglutarimide and polymethyl methacrylate. The airbridge was patterned by electron beam lithography and metal lift-off with bilayer resist. Conductance measurements were performed on the devices at low magnetic fields. The results confirmed both the presence of the elliptical antidot as a negative voltage was applied to the center gate, as well as the nonintrusive nature of the airbridge technique. [S073P2101(00)02502-1].