ISBN 9783843924450

978-3-8439-2445-0, Reihe Physik

Christoph Schönhuber
Inelastic light scattering in the regime of the persistent spin helix

118 Seiten, Dissertation Universität Regensburg (2015), Softcover, A5

Zusammenfassung / Abstract

Spintronics is one of the most promising research fields as it aims to revolutionize conventional information technology. The utilization of an electron’s spin instead of its charge opens new pathways for novel electronic devices and applications based on the spin degree of freedom in semiconductor nanostructures. Essential criteria for the functionality of these modern devices are an accurate control as well as a defined manipulation of spin precession. Any uncontrolled spin dephasing due to spin-orbit interaction, however, bears inevitable disturbances and finally results in a loss of information. This issue may be bypassed by the special situation of a unidirectional spin-orbit field, giving rise to a so called persistent spin helix. As a consequence, the lifetime of the spin polarization is enhanced and a maximum anisotropy in the spin splitting of the conduction band emerges.

This work is a contribution to the current research concerning experimental verification and fundamental characterization of the persistent spin helix state in two-dimensional electron systems. As a powerful tool to investigate the band structure, inelastic light scattering is employed to verify the persistent spin helix state for the first time by means of its distinct anisotropy in the spin splitting. Indeed, a unidirectional spin-orbit field may be realized in different configurations, leading to different manifestations of the persistent spin helix state. A special focus herein lies on the clarification of origins and ramifications, whereby various GaAs quantum wells with particular growth parameters are examined.