Pseudogap Transition in T-shaped Double Dot

Abstract

We investigate the transport properties of the T-shaped arrangement of double-quantum-dot (DQD) as a result from a setup which presents zero-field Kondo splitting and quantum-critical transition. In a particular case, this setup appears as a system of a usual quantum dot (QD) with Kondo resonance coupled to another QD containing one or two discreet levels. We show that the setup formed from a dot presenting Kondo resonance connected to the leads only by the second dot maps the system onto an Anderson impurity with an effective energy hybridization function Δ(ω) proportional to |ω|r where r=1. A similar behavior but with r=2, has been predicted by Dias da Silva et al. (Phys. Rev. Lett. 97:096603, [2006]) for the parallel double quantum dots setup.