Spin excitations in an all-organic double quantum dot molecule
  We realize a strongly coupled double quantum dot in a single all-organic molecule by introducing a non-conjugated bridge in between two identical conjugated moieties. Spin-1/2 Kondo and Kondo enhanced low-energy excitations for respectively the odd and even electron occupation are observed in off-resonant transport. The ground state in the even occupation can be the singlet or the triplet state varying between samples. This observation suggests that both anti-ferromagnetic and ferromagnetic interactions between spins are of the same order of magnitude. 
Max Koole, Jan C. Hummelen, Herre S.J. van der Zant
cond-mat.mes-hall