Determination of the Rashba and Dresselhaus coupling constants using the conductance of a ballistic nanowire

We study the conductance steps of a ballistic nanowire in the presence of a harmonic potential, an in-plane magnetic field, and spin–orbit interactions induced by Rashba and Dresselhaus effects. Calculations of the conductance, at low temperature, using the Landauer–Büttiker formalism, reveal different patterns of steps that are strongly dependent on the magnetic field. Such dependence provides a powerful tool for determining the strengths of the spin–orbit interaction independently, especially in nanowires with low carrier density.

Evolution of the conductance steps as the orientation of the magnetic field varies. The dependence of the conductance steps of a ballistic nanowire on the magnetic field is used to determine the Rashba and Dresselhaus coupling constants independently.Figure optionsDownload as PowerPoint slideHighlights
► We study the quantum steps of the conductance in ballistic nanowire.
► Conductance steps are sensitive to the magnetic field and spin–orbit interaction.
► Negative step disappears at key values of these interactions.
► Rashba and Dresselhaus constants are determined independently from those values.