ELECTRON-ELECTRON-SCATTERING-INDUCED SIZE EFFECTS IN A 2-DIMENSIONAL WIRE

The differential resistance of wires defined in the two-dimensional electron gas in an (Al,Ga)As heterostructure is observed to first increase and then decrease with increasing current. It is demonstrated that this behavior results from the interplay of an enhanced electron-electron-scattering rate (due to current heating of the electron gas), and the partly diffusive nature of boundary scattering in the wire. The data are identified as an experimental observation of the Knudsen maximum and the Poiseuille flow regime in electron transport, and confirm an analogy between electron and gas flow that has been anticipated since the 1950s.