  The spin precession in a cylindrical semiconductor nanowire due to Rashba
spin-orbit coupling has been investigated theoretically using an InAs nanowire
containing a surface two-dimensional electron gas as a model. The eigenstates,
energy-momentum dispersion, and the energy-magnetic field dispersion relation
are determined by solving the Schr\"odinger equation in a cylindrical symmetry
The combination of states with the same total angular momentum but opposite
spin orientation results in a periodic modulation of the axial spin component
along the axis of the wire. Spin-precession about the wires axis is achieved by
interference of two states with different total angular momentum. Because a
superposition state with exact opposite spin precession exists at zero magnetic
field, an oscillation of the spin orientation can be obtained. If an axially
oriented magnetic field is applied, the spin gains an additional precessing
component.
