  Low-dimensional metallic transport is at the heart of modern high-performance
transistors. While the best devices are currently based on III-V heterojunction
quantum-well channels, we demonstrate that much greater performance gains
reside in the unique properties of one-dimensional carbon nanotubes. Using
recent experimental data, we show how the specific features of degenerate
carrier kinetics in metallic nanotubes enable a novel class of quantum-confined
signal detector whose current gain exceeds present transistor technology. We
analyze the key interplay of degeneracy and scattering dynamics on the
transconductance via a microscopically conserving quantum-kinetic description.
