Observation of one electron charge in an enhancement-mode InAs single   electron transistor at 4.2K
  We propose and demonstrate experimentally a novel design of single-electron quantum dots. The structure consists of a narrow band gap quantum well that can undergo a transition from the hole accumulation regime to the electron inversion regime in a single-top-gate transistor configuration. We have observed large size quantization and Coulomb charging energies over 10meV. This quantum dot design can be especially important for scalable quantum computing. 
G.M. Jones, B.H. Hu, C.H. Yang, M.J. Yang, and Y.B. Lyanda-Geller