Strongly electrostatically coupled quantum dots with separate leads

Two strongly electrostatically coupled quantum dots have been realized in a double-quantum-well GaAs/AlGaAs heterostructure by reactive ion etching. The vertically stacked dots are separated by a 40 nm thin AlGaAs barrier with a diameter of less than 0.5 mu m. By contacting the quantum wells separately, each quantum dot has its own two leads allowing to monitor the current through each of the quantum dots. Transport measurements show a strong electrostatic interaction between the dots. This arrangement should allow the investigation of energy transfer between the quantum dots and Kondo physics. (C) 2000 Elsevier Science B.V. All rights reserved.