APS/Alan Stonebraker

Figure 1: Sketch of a mesoscopic ring conductor, based on a two-dimensional electron gas in a layered semiconductor, and coupled to two leads. Rashba spin-orbit interaction couples the electron spin to an effective radial magnetic field (blue) perpendicular to the electron momentum (red) and to the electric field associated with the interface between the two semiconductor structures. For finite spin-orbit coupling, the electron spin cannot adiabatically maintain a fixed orientation with respect to this radial field but precesses around a guiding vector that itself tracks around a conical surface with opening angle $θ$ [see Eq. (1)]. (True adiabaticity would correspond to $θ=90$°.)