How many electrons are needed to flip a local spin?

TL;DR

This paper models the quantum dynamics of a local spin interacting with spin-polarized electrons, estimating the minimum electrons required to flip the spin, thereby advancing understanding of spin transfer at the quantum level.

Contribution

It introduces a fully quantum mechanical approach to analyze spin transfer, improving upon semi-classical models and quantifying the minimum electrons needed for spin flipping.

Findings

Quantum model of spin-electron interaction developed

Estimated minimum electrons needed to flip a local spin

Enhanced understanding of spin transfer phenomena

Abstract

Considering the spin of a local magnetic atom as a quantum mechanical operator, we illustrate the dynamics of a local spin interacting with a ballistic electron represented by a wave packet. This approach improves the semi-classical approximation and provides a complete quantum mechanical understanding for spin transfer phenomena. Sending spin-polarized electrons towards a local magnetic atom one after another, we estimate the minimum number of electrons needed to flip a local spin.