Entanglement and transport through correlated quantum dot

TL;DR

This paper investigates the relationship between quantum entanglement and conductance in a quantum dot system, revealing that maximal conductance does not always coincide with maximal entanglement and analyzing how Kondo resonance affects pairwise entanglement.

Contribution

It provides a detailed analysis of entanglement behavior in quantum dots, especially its relation to conductance and the influence of Kondo resonance, which is a novel insight.

Findings

Maximal conductance does not always match maximal entanglement.

Zero concurrence can coexist with maximal conductance at low hybridization.

Pairwise concurrence vanishes during Kondo resonance.

Abstract

We study quantum entanglement in a single-level quantum dot in the linear-response regime. The results show, that the maximal quantum value of the conductance 2e^2/h not always match the maximal entanglement. The pairwise entanglement between the quantum dot and the nearest atom of the lead is also analyzed by utilizing the Wootters formula for charge and spin degrees of freedom separately. The coexistence of zero concurrence and the maximal conductance is observed for low values of the dot-lead hybridization. Moreover, the pairwise concurrence vanish simultaneously for charge and spin degrees of freedom, when the Kondo resonance is present in the system. The values of a Kondo temperature, corresponding to the zero-concurrence boundary, are also provided.