Semiclassical trace formulae for systems with spin-orbit interactions: successes and limitations of present approaches

We discuss the semiclassical approaches for describing systems with spin-orbit interactions by Littlejohn and Flynn (1991, 1992), Frisk and Guhr (1993), and by Bolte and Keppeler (1998, 1999). We use these methods to derive trace formulae for several two- and three-dimensional model systems, and exhibit their successes and limitations. We discuss, in particular, also the mode conversion problem that arises in the strong-coupling limit.