Theory of the time-resolved Kerr rotation on trapped holes

TL;DR

This paper develops a theoretical model for interpreting time-resolved Kerr rotation experiments on trapped holes in semiconductor nanostructures, enabling extraction of spin relaxation and dephasing rates from experimental data.

Contribution

It introduces an analytical framework for analyzing Kerr rotation signals that accounts for microscopic spin dynamics in trapped hole systems.

Findings

Derived formulas for hole spin polarization

Identified components revealing relaxation and dephasing rates

Provided a method to extract spin rates from experimental data

Abstract

We formulate a model of the time-resolved Kerr rotation experiment on a single hole in a semiconductor nanostructure (e.g., a quantum dot) or on an ensemble of trapped holes (e.g., in a quantum well) in a tilted magnetic field. We use a generic Markovian description of the hole and trion dephasing and focus on the interpretation of the time-resolved signal in terms of the microscopic evolution of the spin polarization. We show that the signal in an off-plane field contains components that reveal both the spin relaxation rate and the spin coherence dephasing rate. We derive analytical formulas for the hole spin polarization, which may be used to extract the two relevant rates by fitting to the measurement data.