Transport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitation

TL;DR

This paper provides semi-analytical predictions for spin-dependent transport and recombination in semiconductors during coherent spin excitation, revealing a doubling of Rabi frequency and multiple nutation frequencies in weakly coupled localized spin pairs.

Contribution

It introduces a semi-analytical model for spin-dependent processes in weakly coupled localized spin pairs during coherent excitation, highlighting frequency doubling and nutation phenomena.

Findings

Rabi frequency doubles when microwave field exceeds Larmor frequency separation

Charge pairs show four nutation frequencies under certain conditions

Derived simple equations for predicting nutation frequencies

Abstract

Semi-analytical predictions for the transients of spin-dependent transport and recombination rates through localized states in semiconductors during coherent electron spin excitation are made for the case of weakly spin-coupled charge carrier ensembles. The results show that the on-resonant Rabi frequency of electrically or optically detected spin-oscillation doubles abruptly as the strength of the resonant microwave field gamma B_1 exceeds the Larmor frequency separation within the pair of charge carrier states between which the transport or recombination transition takes place. For the case of a Larmor frequency separation of the order of gamma B_1 and arbitrary excitation frequencies, the charge carrier pairs exhibit four different nutation frequencies. From the calculations, a simple set of equations for the prediction of these frequencies is derived.