Hole Mobility in GaAs/AlGaAs Quantum Wells
We have studied the low temperature mobility of low disorder two-dimensional hole systems in GaAs/AlGaAs quantum wells. We found that the mobility depended non-monotonically on the hole density, peaking at an intermediate density and falling for further increased density. This is in sharp contrast to electrons in this density range which would continue to increase in mobility as the density is increased. We performed simple scattering calculations which indicated that interface roughness scattering could limit the mobility at high density, but using the same parameters in a similar two-dimensional electron gas grown during the course of our experiment showed that the scattering parameters would have to be different to fit the electron data. This leaves open the possibility in the hole systems for more complicated scattering between the spin-split subbands of the quantum well.
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