Kondo effect in quantum dots coupled to ferromagnetic leads with noncollinear magnetizations

TL;DR

This paper investigates how noncollinear ferromagnetic lead magnetizations influence the Kondo effect in quantum dots, revealing that the zero bias anomaly splitting diminishes with increasing angle and behaves differently in symmetric versus asymmetric couplings.

Contribution

It provides a detailed analysis of the angle-dependent Kondo effect in quantum dots with noncollinear ferromagnetic leads using non-equilibrium Green's functions.

Findings

Zero bias Kondo anomaly splitting decreases with increasing magnetization angle.

In symmetric coupling, the splitting vanishes for antiparallel magnetizations.

In asymmetric coupling, the splitting remains finite even at antiparallel configuration.

Abstract

Non-equilibrium Green's function technique has been used to calculate spin-dependent electronic transport through a quantum dot in the Kondo regime. The dot is described by the Anderson Hamiltonian and is coupled either symmetrically or asymmetrically to ferromagnetic leads, whose magnetic moments are noncollinear. It is shown that the splitting of the zero bias Kondo anomaly in differential conductance decreases monotonically with increasing angle between magnetizations, and for antiparallel configuration it vanishes in the symmetrical case while remains finite in the asymmetrical one.