SEPARATION OF EDGE CHANNELS BY A MACROSCOPIC DISTANCE IN A HALF-GATEDGAAS ALXGA1-XAS HETEROSTRUCTURE/

We show that the inter-edge-channel scattering of a two-dimensional el ectron gas in the quantum Hall regime can be dramatically suppressed w hen the confining potential at the boundaries of the sample is altered . The confining potential is changed by making use of a half-gated GaA s/AlxGa1-xAs heterostructure. In this configuration, the (spin-split) edge channels on the same side of the sample can be separated by a mac roscopic (approximately 1 mm) distance. We use an interior contact to detect or feed the innermost edge channels as opposed to quantum point contacts or contacts with cross gates which are coupled to the outerm ost edge channels. Due to the large spatial separation of the respecti ve edge channels, it is shown that the inter-edge-channel scattering c an be totally suppressed and therefore the equilibration length become s arbitrarily long.