  Electron spin precession in nonuniform Rashba-Dresselhaus two-dimensional
electron systems along arbitrary continuous paths is investigated. We derive an
analytical formula to describe the spin vectors (expectation values of the
injected spin) in such conditions using a contour-integral method. The obtained
formalism is capable of dealing with the nonuniformity of the Rashba spin-orbit
field due to the inherent random distribution of the ionized dopants, and can
be applied to curved one-dimensional quantum wires. Interesting examples are
given, and the modification to the spin precession pattern in a
Rashba-Dresselhaus channel when taking the random Rashba field into account is
shown.
