Scattering anisotropy in HgTe (013) quantum well

We report on a detailed experimental study of the electron transport anisotropy in HgTe (013) quantum well 22 nm width directions [100] and [031¯] as density function n. The is absent at minimal near charge neutrality point. increases with increase n reaches about 10% when Fermi level within first subband H1. There sharp (up to 60%) second E2. conclude that effect due small intra-subband anisotropic interface roughness scattering, one strongly inter-subband but microscopical reason for such strong change remains unknown.