Single charge sensing and transport in double quantum dots fabricated   from commercially grown Si/SiGe heterostructures
  We perform quantum Hall measurements on three types of commercially available modulation doped Si/SiGe heterostructures to determine their suitability for depletion gate defined quantum dot devices. By adjusting the growth parameters, we are able to achieve electron gases with charge densities 1-3 X 10^{11}/cm^2 and mobilities in excess of 100,000 cm^2/Vs. Double quantum dot devices fabricated on these heterostructures show clear evidence of single charge transitions as measured in dc transport and charge sensing and exhibit electron temperatures of 100 mK in the single quantum dot regime. 
C. Payette, K. Wang, P. J. Koppinen, Y. Dovzhenko, J. C. Sturm, and J.   R. Petta
cond-mat.mes-hall quant-ph