Kondo screening cloud in a double-quantum dot system
  We analyze the transport properties of two artificial magnetic impurities coupled togethervia a tunable RKKY interaction mediated by conduction electrons of a finite size one dimensional wire. We show that the sign of the RKKY interaction can be controlled by gating the wire. We investigate the interplay between finite size effects and RKKY interaction and found that the two artificial impurities start to interact each-other as soon as the Kondo screening cloud length becomes larger that the length of the wire. This should allow to give a lower experimental estimate of the Kondo screening cloud length. 
Pascal Simon