Theory of the spin relaxation of conduction electrons in silicon

TL;DR

This paper introduces a pseudopotential model to study phonon-induced spin relaxation in silicon, revealing complex interference effects and providing predictions consistent with experimental data across temperature ranges.

Contribution

It presents a new pseudopotential approach that uncovers the interplay of Elliott and Yafet processes in silicon's spin relaxation, challenging previous assumptions about dominant scattering mechanisms.

Findings

Spin relaxation times follow a T^{-3} dependence.

Interference effects suppress intravalley spin-flip scattering above 120 K.

Predictions include valley anisotropy and hot electron relaxation rates.

Abstract

A realistic pseudopotential model is introduced to investigate the phonon-induced spin relaxation of conduction electrons in bulk silicon. We find a surprisingly subtle interference of the Elliott and Yafet processes affecting the spin relaxation over a wide temperature range, suppressing the significance of the intravalley spin-flip scattering, previously considered dominant, above roughly 120 K. The calculated spin relaxation times $T_1$ agree with the spin resonance and spin injection data, following a $T^{-3}$ temperature dependence. The valley anisotropy of $T_1$ and the spin relaxation rates for hot electrons are predicted.