Ballistic cooling in a wideband two-dimensional electron gas bolometric mixer

We show that bolometric mixers fabricated from a high mobility two-dimensional electron gas can reach a regime where electron energy relaxation is dominated by ballistic, rather than diffusive, outflow of excited electrons. This ballistic cooling mechanism establishes the maximum physical limit on mixer speed for a transit-time limited device. Intermediate frequency bandwidths of nearly 40 GHz have been obtained in devices with channel lengths >1 mum in ballistically cooled devices. (C) 2002 American Institute of Physics.