Two-dimensional hole gas at a semiconductor heterojunction interface

Abstract
We report the first observation of a two‐dimensional hole gas (2DHG) at a semiconductor heterojunction interface (GaAs/AlxGa1−xAs). Low‐temperature angular‐dependent Shubnikov‐de Haas measurements demonstrate the two dimensionality of the system and yield a carrier surface density of 7×1011 cm−2. From the temperature dependence of the magneto oscillations we derive an effective mass of 0.35±0.1m0 for the carriers. Hall measurements establish a He temperature mobility of μ≈1700 cm2/V sec.