Spin splitting and weak localization in (110) GaAs/AlxGa1−xAs quantum wells

We investigate both theoretically and experimentally the spin-orbit effects on the weak localization in a (110) GaAs two-dimensional electron gas. We analyze the role of two different terms in the spin splitting of the conduction band: the Dresselhaus terms, which arise due to the lack of inversion center in the bulk GaAs, and the Rashba terms, which are caused by the asymmetry of the quantum well. It is shown that in ${\mathrm{A}}_3$ ${\mathrm{B}}_5$ quantum wells the magnetoresistance due to the weak localization depends qualitatively on the orientation of the well. In particular, it is demonstrated that the (110) geometry has a distinctive feature that in the absence of the Rashba terms the ``antilocalization'' effect, i.e., the positive magnetoresistance, does not exist. Calculation of the weak antilocalization magnetoresistance is found to be in excellent agreement with experiments.