Control of Electron Spin Coherence Using Landau Level Quantization in a Two-Dimensional Electron Gas

TL;DR

This study investigates how Landau level quantization in a two-dimensional electron gas affects electron spin coherence times and precession frequencies, revealing a coupling between spin and orbital states through experimental and theoretical analysis.

Contribution

It introduces a theoretical model explaining how Landau level population influences spin coherence, supported by experimental observations in quantum wells.

Findings

Oscillations in spin coherence time and g-factor match Shubnikov-de Haas oscillations.

Landau level population causes inhomogeneous dephasing, limiting spin coherence.

Coupling between spin and orbital states is demonstrated experimentally.

Abstract

Time-resolved optical measurements of electron spin dynamics in modulation doped InGaAs quantum wells are used to explore electron spin coherence times and spin precession frequencies in a regime where an out of plane magnetic field quantizes the states of a two-dimensional electron gas into Landau levels. Oscillatory features in the transverse spin coherence time and effective g-factor as a function of applied magnetic field exhibit a correspondence with Shubnikov-de Haas oscillations, illustrating a coupling between spin and orbital eigenstates. We present a theoretical model in which inhomogeneous dephasing due to the population of different Landau levels limits the spin coherence time and captures the essential experimental results.