Weak antilocalization in InAs quantum wires

We study the spin–orbit interaction in diffusive InAs quantum wires ranging from 4 to View the MathML source in width by means of weak antilocalization (WAL) analysis. Our experimental data can be well fitted using the 2D model, the 1D model and a newly developed dimensional crossover model. However, the physics behind these models is quite different. The 1D and DC models take the wire width into account and show a width-independent spin–orbit interaction, in contrast to the 2D model which incorrectly shows an increase of the spin–orbit interaction with decreasing width. Our experimental data qualitatively agrees with the predicted decrease of the WAL peak amplitude as the wire becomes narrower than the spin–orbit length. However, this effect is not accompanied by the expected suppression of the extracted spin–orbit interaction, obtained from the 1D and the crossover model.