Quantized conductance in a heterostructurally defined Ga0.25In0.75As/InP quantum wire

We report on the observation of quantized conductance up to 10 It in expitaxially regrown, heterostructurally defined, 100-nm-wide Ga0.25In0.75As/InP quantum wires. In addition to the plateaus at integer steps of 2e(2)/h, we observe plateaus at 0.2(2e(2)/h), 0.7(2e(2)/h), and 1.5(2e(2)/h), indicating spin polarization at zero magnetic field. Of these, the first two plateaus appear to evolve into one at around 0.5(2e(2)/h) when the sample is subjected to a magnetic field parallel to the quantum wire. The observation of quantized conductance is made possible by the substantial improvement in the quality of the interface by regrowth. (C) 1997 American Institute of Physics.