Single hole transistor in a p-Si/SiGe quantum well
  A single hole transistor is patterned in a p-Si/SiGe quantum well by applying voltages to nanostructured top gate electrodes. Gating is achieved by oxidizing the etched semiconductor surface and the mesa walls before evaporation of the top gates. Pronounced Coulomb blockade effects are observed at small coupling of the transistor island to source and drain. 
U. Doetsch, U. Gennser, T. Heinzel, S. Luescher, C. David, G.   Dehlinger, D. Gruetzmacher, and K. Ensslin