Terahertz waveguide spectroscopy of two-dimensional plasmons in GaAs

Abstract

The electrical characteristics of high-mobility, two-dimensional electron gas (2DEG) systems, such as GaAs quantum wells, have been well-studied at low frequencies and in extreme conditions of high magnetic fields and ultralow temperatures. While high-frequency excitations of 2DEGs have been examined to some extent from microwave to terahertz (THz) frequencies, a fundamental understanding of the physical properties of 2DEGs in this range have by no means been mastered. To address this matter, this thesis focused on studying a fundamental, high-frequency collective excitation, known as the plasmon, to better understand plasmon damping and coupling mechanisms in GaAs quantum well 2DEGs. The experiments utilized THz waveguide spectroscopy to study the low-temperature behavior of 2D plasmons.