Sakano Rui, Kawakami Norio
Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043.
J Electron Microsc (Tokyo). 2005;54 Suppl 1:i57-60. doi: 10.1093/jmicro/54.suppl_1.i57.
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).
