Confinement symmetry, mobility anisotropy, and metallic behavior in (311)AGaAs two-dimensional holes

We study two-dimensional hole systems confined to (311)A GaAs quantum wells . Such samples exhibit an in-plane mobility anisotropy. Al constant hole de nsity, we vary the symmetry of the quantum well potential, and thus the spi n-orbit interaction-induced spin splitting, and measure the temperature dep endence of the resistivity along two different in-plane current directions, in a regime where the samples exhibit metallic behavior. Both the symmetry and the current direction have a significant effect on the metallic behavi or. The results point to the importance of both intersubband and interface- roughness scattering in any quantitative explanation of the low-temperature transport characteristics of this system.