Charge and spin dynamics in a two dimensional electron gas

TL;DR

This paper reviews various time-resolved optical experiments used to investigate charge and spin dynamics in a high mobility two-dimensional electron gas in GaAs/AlGaAs heterojunctions, highlighting methods to measure carrier and spin properties.

Contribution

It demonstrates how combined Kerr effect experiments can simultaneously extract carrier lifetimes and spin dephasing times in a single measurement.

Findings

Carrier lifetimes and spin dephasing times are measurable via optical experiments.

Charge mobility can be directly obtained from carrier diffusion coefficients.

Combined Kerr experiments effectively determine both charge and spin dynamics.

Abstract

A number of time resolved optical experiments probing and controlling the spin and charge dynamics of the high mobility two-dimensional electron gas in a GaAs/AlGaAs heterojunction are discussed. These include time resolved reflectivity, luminescence, transient grating, magneto-optical Kerr effect, and electro-optical Kerr effect experiments. The optical experiments provide information on the carrier lifetimes and spin dephasing times, as well as on the carrier diffusion coefficient which directly gives the charge mobility. A combination of the two types of Kerr experiments, shows to be useful in extracting both the carrier lifetimes and spin dephasing times in a single experiment.