We study transport through two quantum dots coupled by a Ruderman-Kittel-Kasuya-Yoshida interaction as a function of temperature and magnetic field. By applying the numerical renormalization group method, we obtain the transmission and the linear conductance. At zero temperature and magnetic field, we observe a quantum phase transition between the Kondo screened state and a local spin singlet as the RKKY interaction is tuned. Above the critical RKKY coupling, the Kondo peak is split. However, we find that both finite temperature and magnetic field restore the Kondo resonance. Our results agree well with recent transport experiments on gold grain quantum dots in the presence of magnetic impurities.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 24 Jul 2007|