Universal signature of ballistic transport in nanoscale field effect transistors

We present a universal signature of ballistic transport in field effect transistors with channel lengths down to 25 nm and widths up to 100 μm. By measuring with a two and four-probe setup the derivative of the differential conductance with respect to the gate voltage for finite drain bias a splitting is obtained, which is shown to be a clear indication of electrons traversing the channel conserving their initial energy.