Coulomb blockade and Quantum Critical Points in Quantum Dots
arXiv:cond-mat/0406316 · doi:10.1016/j.physb.2005.01.427
Abstract
An ultrasmall quantum dot coupled to a lead and to a quantum box (a large quantum dot) is investigated. Tuning the tunneling amplitudes to the lead and box, we find a line of unstable non-Fermi-liquid fixed points as function of the gate potentials of the quantum dots, extending to arbitrary charging energies on the small and large quantum dots. These quantum-critical fixed points possess a finite residual entropy. They govern the cross over from one Fermi-liquid regime to another, characterized by distinct (high and low) conductance values.
2 pages, 3 figures, Elsevier Science style