Spin Nomenclature for Semiconductors and Magnetic Metals

TL;DR

This paper clarifies the different conventions for spin nomenclature in semiconductors and magnetic metals, aiming to reduce confusion in the rapidly growing field of spintronics by relating terminology to fundamental angular momentum principles.

Contribution

It provides a unified framework for understanding and translating spin-related terminology across semiconductor and magnetic metal research communities.

Findings

Clarifies the meaning of 'spin-up' and 'majority spin' in different contexts.

Relates spin polarization definitions to angular momentum conservation.

Provides guidance for consistent terminology in spintronics research.

Abstract

The different conventions used in the semiconductor and magnetic metals communities can cause confusion in the context of spin polarization and transport in simple heterostructures. In semiconductors, terminology is based on the orientation of the electron spin, while in magnetic metals it is based on the orientation of the moment. In the rapidly expanding field of spintronics, where both semiconductors and metallic metals are important, some commonly used terms ("spin-up," "majority spin") can have different meanings. Here, we clarify nomenclature relevant to spin transport and optical polarization by relating the common physical observables and "definitions" of spin polarization to the fundamental concept of conservation of angular momentum within a well-defined reference frame.