  We discuss the realization of the quantum-critical non-Fermi liquid state,
originally discovered within the two-impurity Kondo model, in double
quantum-dot systems. Contrary to the common belief, the corresponding fixed
point is robust against particle-hole and various other asymmetries, and is
only unstable to charge transfer between the two dots. We propose an
experimental set-up where such charge transfer processes are suppressed,
allowing a controlled approach to the quantum critical state. We also discuss
transport and scaling properties in the vicinity of the critical point.
