Orbital Kondo effect and spin polarized transport through quantum dots

TL;DR

This paper investigates how magnetic fields influence spin-dependent transport in coupled quantum dots, revealing conditions for the orbital Kondo effect and spin filtering capabilities.

Contribution

It introduces a detailed analysis of the orbital Kondo effect in quantum dots under magnetic fields, highlighting spin filtering phenomena.

Findings

Kondo resonance can be spin-selective under Zeeman splitting.

Quantum dots can function as efficient spin filters.

Magnetic field tuning enables control over spin-dependent transport.

Abstract

The coherent spin dependent transport through a set of two capacitively coupled quantum dots placed in a magnetic field is considered within the equation of motion method. The magnetic field breaks the spin degeneracy. For special choices of gate voltages the dot levels are tuned to resonance and the orbital Kondo effect results. For different Zeemann splittings at the dots the Kondo resonance can be formed for only one spin channel. In this case the system operates as an efficient spin filter.