Emergent Electric Polarization by Kondo Effect in a Triangular Triple Quantum Dot

TL;DR

This paper investigates how Kondo effects in a triangular triple quantum dot lead to emergent electric polarization, revealing the interplay of spin and charge and its dependence on hybridization strength through numerical analysis.

Contribution

It introduces a model showing how electric polarization arises from Kondo effects in a triangular quantum dot, highlighting the role of hybridization in this process.

Findings

Electric polarization emerges due to Kondo effects in the quantum dot.

The polarization depends on hybridization strength, which can be experimentally controlled.

Numerical renormalization group analysis elucidates the spin-charge interplay.

Abstract

A triangular triple quantum dot gives various Kondo effects, such as the emergence of an electric polarization accompanied by a complete compensation of spin degrees of freedom. The interplay of spin and charge of electrons in quantum dots is investigated using an Anderson model with an equilateral triangular spin cluster, in which a single electron state at one site is hybridized with a conduction band in a lead. The numerical renormalization group analysis shows how a nonzero electric polarization develops with local electrons traveling in the loop and how it depends on the hybridization strength as an experimentally controllable parameter in the Kondo effect.