Crossover from diffusive to ballistic transport as a function of frequency in a two dimensional electron gas

Ballistic transport is nothing but an electron transport in the limit (/spl omega//spl tau//sub m/ > 1); the electron move without scattering between electric field cycles. Diffusive transport can be defined as the lower frequency range (/spl omega//spl tau//sub m/<1); in the diffusive limit there are many scattering events between electric field cycles. Here we measure for the first time the crossover from diffusive to ballistic transport as a function of frequency in a dc contacted 2DEG.