Detecting Kondo Entanglement by Electron Conductance

TL;DR

This paper proposes a method to detect quantum entanglement in Kondo systems by measuring electron conductance in a double quantum dot setup, revealing the spatial distribution of the Kondo cloud.

Contribution

It establishes a relation between entanglement and conductance in the orbital Kondo regime, enabling detection of the Kondo cloud through electrical measurements.

Findings

Derived a conductance-entanglement relation under weak SU(2) symmetry breaking

Proposed a method to spatially map the Kondo cloud

Connected many-body Kondo states to measurable conductance signals

Abstract

Quantum entanglement between an impurity spin and electrons nearby is a key property of the single-channel Kondo effects. We show that the entanglement can be detected by measuring electron conductance through a double quantum dot in an orbital Kondo regime. We derive a relation between the entanglement and the conductance, when the SU(2) spin symmetry of the regime is weakly broken. The relation reflects the universal form of many-body states near the Kondo fixed point. Using it, the spatial distribution of the entanglement, hence, the Kondo cloud, can be detected, with breaking the symmetry spatially nonuniformly by electrical means.