Raman studies of intrasubband plasmons in laterally modulated two-dimensional electron gases

Abstract

We report an inelastic light-scattering study of the intrasubband plasmons of a single two-dimensional electron gas (2DEG) at a GaAs/Al"Gal "As heterointerface under a grating Schottky gate with a period comparable to the plasmon wavelength. Gaps appear in the plasmon dispersion relation because of the spatially periodic screening by the gate, and these are successfully modeled using a scattering matrix calculation of the electromagnetic response of the system. Biasing the gate periodically modulates the 2DEG carrier density, and has a striking e6ect on the plasmon dispersion relation that cannot be fully explained within the existing theoretical framework.

Spatially resolved Raman scattering from hot acoustic and optic plasmons

“…10 and 11͒, has recently been used to characterize electronic devices. 7,12 In the backscattering geometry employed here ͓Fig. 1͑a͔͒, the Raman wave-vector transfer in the plane of the 2DEG can be varied by rotating the sample relative to the incident and scattered light wave vectors, enabling the determination of the energy dispersion of the excitations with wave vector q.…”