Metal-Insulator Transition in a Disordered Two-Dimensional Electron Gas   in GaAs-AlGaAs at zero Magnetic Field
  A metal-insulator transition in two-dimensional electron gases at B=0 is found in Ga(Al)As heterostructures, where a high density of self-assembled InAs quantum dots is incorporated just 3 nm below the heterointerface. The transition occurs at resistances around h/e^2 and critical carrier densities of 1.2 10^11cm^-2. Effects of electron-electron interactions are expected to be rather weak in our samples, while disorder plays a crucial role. 
E. Ribeiro, R. Jaeggi, T. Heinzel, K. Ensslin, G. Medeiros-Ribeiro,   and P.M. Petroff