We study numerically and analytically the dynamical (ac) conductance through a two-dot system, where only one of the dots is coupled to the leads but it is also side coupled to the other dot through an antiferromagnetic exchange Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction. In this case, the RKKY interaction gives rise to a "two-stage Kondo effect" where the two spins are screened by two consecutive Kondo effects. We formulate a renormalized scaling theory that captures remarkably well the crossover from the strongly conductive correlated regime to the low temperature, low conductance state. Our analytical formulas agree well with our numerical renormalization group results. The frequency-dependent current noise spectrum is also discussed.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jan 17 2008|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics