Field induced tunneling in SiGe wires.

Source-drain characteristics of narrow wires, fabricated from high mobility SiGe two-dimensional electron gases, have been investigated at different temperatures and gate biases. The experimental behavior, although reminiscent of Coulomb blockade effects, is instead well accounted for by assuming that the wires are insulating, due to charge depletion, and that the current is due to field-induced tunneling.