Swapping entangled Kondo resonances in parallel-coupled double quantum dots

TL;DR

This paper investigates how entangled Kondo resonances in parallel-coupled double quantum dots can be swapped by tuning interdot exchange and coupling asymmetry, revealing a many-body coherence effect with potential quantum computing applications.

Contribution

It demonstrates the controllable swapping of entangled Kondo resonances in double quantum dots through tuning system parameters, a novel many-body quantum effect.

Findings

Resonance swapping occurs with increasing J or asymmetry ratio

Line shapes of conductance are interchanged during swapping

Peak in differential conductance at critical parameter values

Abstract

Strong electron and spin correlations are studied in parallel-coupled double quantum dots with interdot spin superexchange $J$. In the Kondo regime with {\it}{degenerate} dot energy levels, a coherent transport occurs at zero temperature, where two entangled (bonding and antibonding) resonances are formed near the Fermi energy. When increasing $J$ or the dot-lead parallel-coupling \QTR{it}{asymmetry} ratio $\Gamma_{2}/\Gamma_{1}$, a swap between two entangled resonances occurs and the line shapes of the linear conductance are interchanged. The zero-bias differential conductance shows a peak at the critical values. Such a peculiar effect with the virtue of many-body coherence may be useful in future quantum computing.