Large positive magnetoresistance in periodically modulated two-dimensional electron gas formed on self-organized GaAs multiatomic steps

We study magneto-transport properties of two-dimensional electron gas (2DEG) subjected to a periodic potential with a period of 60–70 nm, where the potential modulation is realized by periodically corrugated InGaAs channel layer formed on self-organized GaAs multiatomic steps. We find a large positive magnetoresistance (MR) when the current is perpendicular to the potential modulation, while such positive resistance is not observed for the current parallel to the potential modulation. It is also found that the amplitude of MR oscillation for current perpendicular to the potential modulation is extremely large over 3.5 T, and is modulated in 2–3.5 T. In addition, we also find the anisotropy in electron mobility. The results can be explained by the large potential modulation in the lateral surface superlattice (LSSL) and associating modulation of Landau subbands in LSSL.