title: Conductance through two dots coupled in series: application of the exact solution.
abstract: Using the exact Bethe-ansatz solution, we study the conductance through symmetric and asymmetric double-dot (DD) systems in the Kondo regime, where two quantum dots are coupled in series. The application of the Ward-Takahashi identity enables us to compute the conductance at low temperatures. For strong inter- and intra-dot Coulomb repulsions with weak inter-dot tunneling, we discuss how the Kondo effect evolves for an asymmetric DD system as well as a symmetric DD system in a magnetic field. In particular, we clarify that the conductance is decreased (increased) in the asymmetric DD (symmetric DD in a field), reflecting that the Kondo effect due to inter-dot charge fluctuations is suppressed (enhanced).
authors.affiliation: Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043. sakano@tp.ap.eng.osaka-u.ac.jp
authors.forename: Rui
authors.initials: R
authors.lastname: Sakano
authors.forename: Norio
authors.initials: N
authors.lastname: Kawakami