Origins of anisotropic linear magnetoresistance with isotropic mobility in Cd3As2 films on GaAs[110]

Abstract

Thin film synthesis allows for the potential to orient crystals in different orientations, permitting measurement of orientation-dependent material aspects such as band structures and transport anisotropy. Here, Dirac semimetal Cd3As2 films are epitaxially grown on GaAs[110] substrates, which has a [001] orientation in-plane. Films contain domains of two different c-axis orientations resulting from an aligned a-axis in-plane. Magnetoresistance measurements performed along both [11¯0] and [001] substrate directions reveal similar mobility and carrier concentration, but much larger magnetoresistance along the [001] direction, which can be explained by the guiding center diffusion model as arising from anisotropic disorder and different atomic spacings.