We study the tuning mechanisms of Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interaction between two lateral quantum dots in the Kondo regime. At zero magnetic eld we observe the expected splitting of the Kondo resonance and estimate the non-local coupling strength as a function of the asymmetry between the two Kondo temperatures. At nite magnetic elds a chiral coupling between the quantum dots is observed in the Kondo chessboard and we probe

Mesoporous GaAs double layers with different porosities and thicknesses up to 7
m are formed on highly doped p-type 4 inch GaAs substrates by means of electrochemical etching in highly concentrated hydrofluoric acid electrolytes. Small 111 oriented pyramids form at the interface between porous layer and substrate if etching current densities below 7.5mAcm−2 are applied. Porous double layers with different porosities are obtained by varying simultaneously