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

Abstract

We report on the observation of quantized conductance up to 10 K in epitaxially regrown, heterostructurally defined, 100-nm-wide Ga0.25In0.75As/InP quantum wires. In addition to the plateaus at integer steps of 2e2/h, we observe plateaus at 0.2(2e2/h), 0.7(2e2/h), and 1.5(2e2/h), indicating spin polarization at zero magnetic field. Of these, the first two plateaus appear to evolve into one at around 0.5(2e2/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.