Positioning and numbering Ge quantum dots for effective quantum tunneling devices

The authors have demonstrated a simple method to precisely control the number and the position of nanometer-scaled Ge quantum dots (QDs) embedded in SiO
₂
or Si
₃
N
₄
tunnel barriers via thermally oxidizing pre-patterned nanostructures. A single Ge QD in the core or twin Ge QDs near the edges of the nanotrench could be realized by modulating the initial nanostructure's dimensions and the spacer's materials. This method offers great promise to realize effective single electron transistors and coupled QD devices for single charge manipulations.