Large Anisotropy of Electron Mobilities in Laterally Modulated Two-Dimensional Systems Grown on the (775)B-Oriented GaAs Substrates by Molecular Beam Epitaxy

We have investigated the transport properties of electron gas in a GaAs/(GaAs)4(AlAs)2 quantum well with a regularly corrugated upper interface formed on (775)B-oriented GaAs substrates by molecular beam epitaxy (MBE). The electron mobility perpendicular to the corrugation (µ⊥) was suppressed to 1/70th of that parallel to the corrugation (µ∥) for a quantum well with a well width of Lw=5 nm at a temperature of 10 K, and µ⊥ with a thin Lw of 5 nm monotonically increased with increasing temperature (10–300 K). These results suggest that the lateral potential induced by the thickness modulation is so strong in the nominally 5-nm-thick quantum well that the electron gas has a quasi-one-dimensional nature.