Full counting statistics of spin transfer through ultrasmall quantum dots

TL;DR

This paper investigates the full counting statistics of spin-polarized electron transfer through ultrasmall quantum dots, revealing new correlations between spin-up and spin-down electrons that could advance spintronics and Kondo effect studies.

Contribution

It introduces a method to calculate spin-resolved full counting statistics using the Anderson model, including Coulomb interactions, and uncovers novel spin flow correlations.

Findings

Confirmed charge transfer statistics results

Discovered new spin flow correlations

Potential tool for Kondo effect investigation

Abstract

We analyze the spin-resolved full counting statistics of electron transfer through an ultrasmall quantum dot coupled to metallic electrodes. Modelling the setup by the Anderson Hamiltonian, we explicitly take into account the onsite Coulomb repulsion $U$. We calculate the cumulant generating function for the probability to transfer a certain number of electrons with a preselected spin orientation during a fixed time interval. With the cumulant generating function at hand we are then able to calculate the spin current correlations which are of outmost importance in the emerging field of spintronics. We confirm the existing results for the charge statistics and report the discovery of the new type of correlation between the spin-up and -down polarized electrons flows, which has a potential to become a powerful new instrument for the investigation of the Kondo effect in nanostructures.