Theory of Spin-Dependent Phonon-Assisted Optical Transitions in Silicon

TL;DR

This paper develops a theoretical framework linking spin polarization and luminescence in silicon, explaining phonon-assisted optical transitions and their dependence on phonon modes, spin-orbit coupling, and doping.

Contribution

It introduces a comprehensive theory connecting spin polarization with phonon-assisted optical transitions in silicon, explaining recent experimental observations.

Findings

Longitudinal and transverse phonon-assisted transitions behave oppositely.

Spin-orbit coupling influences transition probabilities.

Doping affects the spin-dependent optical processes.

Abstract

A theory for the relation between the spin polarization and luminescence in silicon is presented. The theory provides intuitive relations for phonon-assisted optical transitions between the conduction and valence band edges. It is shown that an opposite behavior of longitudinal and transverse optical phonon-assisted transitions is responsible to recent experimental results of spin injection into silicon. The effects of spin-orbit coupling and doping are studied in detail.