Correlated electron tunneling through two separate quantum dot systems with strong capacitive interdot coupling.

A system consisting of two independently contacted quantum dots with a strong electrostatic interaction shows an interdot Coulomb blockade when the dots are weakly tunnel coupled to their leads. How the blockade can be overcome by correlated tunneling when tunnel coupling to the leads increases is studied experimentally. The experimental results are compared with numerical renormalization group calculations using predefined (measured) parameters. Combining our experimental and theoretical results we identify transport through Kondo correlations due to the electrostatic interaction between the two dots.