Fano resonance and zero-bias anomaly in parallel double quantum dots coupled to Luttinger liquid leads

Abstract

We study the nonequilibrium transport through a parallel-coupled double quantum dot coupled to Luttinger liquid leads using the nonequilibrium Green's function method. A current formula is derived, where the inter-dot tunneling, the intralead interaction, and asymmetric dot-lead coupling are taken into account. The interplay of these interactions on the differential conductance is investigated. The differential conductance of the double-dot system exhibits the coexistence of zero-bias dip and Fano resonance for asymmetric coupling. The zero-bias dip of differential conductance scales onto a single universal curve for different temperature with the same scaling exponent as a system of Kondo dot. As temperature increases, the zero-bias minimum is gradually lifted.