Fabrication and characterization of an undoped GaAs/AlGaAs quantum dot   device
  We demonstrate the development of a double quantum dot with an integrated charge sensor fabricated in undoped GaAs/AlGaAs heterostructures using a double top-gated design. Based on the evaluation of the integrated charge sensor, the double quantum dot can be tuned to a few-electron region. Additionally, the inter-dot coupling of the double quantum dot can be tuned to a large extent according to the voltage on the middle gate. The quantum dot is shown to be tunable from a single dot to a well-isolated double dot. To assess the stability of such design, the potential fluctuation induced by 1/f noise was measured. Based on the findings herein, the quantum dot design developed in the undoped GaAs/AlGaAs semiconductor shows potential for the future exploitation of nano-devices. 
Hai-Ou Li, Gang Cao, Ming Xiao, Jie You, Da Wei, Tao Tu, Guang-Can   Guo, Hong-Wen Jiang and Guo-Ping Guo
cond-mat.mes-hall quant-ph