Quantum Hall effect in wide parabolic GaAs/AlxGa1−xAs wells

Parabolic GaAs/${\mathrm{Al}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As wells are used to create thick (>1000 Å) spatially uniform layers of electron gas with low-temperature mobility μ=(0.2–2.5)×${10}^5$ ${\mathrm{cm}}^2$/V sec. Measurements of the integer quantum Hall effect in a 4000-Å-wide parabolic well as the well is partially filled with electrons are used to study the transition from two-dimensional toward three-dimensional behavior.