Spectrum of Landau Levels in GaAs Quantum Wells

TL;DR

This study investigates the Landau level spectrum in GaAs quantum wells using optical and electrical measurements under magnetic fields, revealing discrete interband transitions and spin splittings.

Contribution

It provides experimental observation and analysis of Landau levels and spin splittings in GaAs quantum wells, comparing results with theoretical calculations.

Findings

Discrete Landau level transitions identified

Energy splitting matches combined conduction and valence band spin splittings

Experimental results agree with numerical calculations

Abstract

We have studied the optical and electrical spectra from an n i p LED as a function of magnetic field. This sample incorporated three GaAs quantum wells in the intrinsic region. This device had excess n type doping and as a result. The quantum wells were populated by a two dimension Landau electron gas. The broad B0 field emission band evolved into a series of discrete features in the presence of a magnetic field. These were identified as interband transitions between the different values of l. Landau levels associated with the sub-bands, with the selection rule. An energy splitting between the two polarised components was observed for each Landau level transition. This was found to be equal to the sum of the conduction and valence band spin splittings. We used the know value of electron g factor to determine the valence band spin splittings. Our experimental values were compared to the numerically calculated values and were found to be in reasonable agreement.