Probing the band structure of a two-dimensional hole gas using a one-dimensional superlattice.

Abstract

Using a one-dimensional superlattice we have mapped out the Fermi surface of a two-dimensional (2D) hole gas in a GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As heterojunction grown on the (311)A surface of GaAs. This follows our observation of commensurability magnetoresistance oscillations from a weakly one-dimensionally modulated (311)A 2D hole gas that is confined to square and triangular quantum wells. The dependence of the oscillations on the modulation direction in the (311)A plane reflects its known k-space anisotropy. This method is a minimally invasive probe of the Fermi surface of high-mobility 2D systems. \textcopyright{} 1996 The American Physical Society.