Transmission in double quantum dots in the Kondo regime: Quantum-critical transitions and interference effects

TL;DR

This paper investigates electron transmission in double quantum dots within the Kondo regime, revealing quantum-critical transitions and interference effects through exact expressions and numerical methods.

Contribution

It provides an exact expression for transmission using many-body Green's functions and maps the system to an Anderson impurity model for analysis.

Findings

Identification of different Kondo regimes including split-peak phases

Observation of a quantum critical transition between Kondo and unscreened phases

Analysis of interference effects in transmission

Abstract

We study the transmission through a double quantum-dot system in the Kondo regime. An exact expression for the transmission coefficient in terms of fully interacting many-body Green's functions is obtained. By mapping the system into an effective Anderson impurity model, one can determine the transmission using numerical renormalization-group methods. The transmission exhibits signatures of the different Kondo regimes of the effective model, including an unusual Kondo phase with split peaks in the spectral function, as well as a pseudogapped regime exhibiting a quantum critical transition between Kondo and unscreened phases.