Magnetoplasma excitations in interacting GaAs disks

TL;DR

This study examines how reducing the distance between GaAs disks in a 2D electron system affects magnetoplasmon dispersion, revealing modifications in collective modes through magneto-optical THz spectroscopy.

Contribution

It demonstrates the impact of inter-disk coupling on magnetoplasmon dispersion in a GaAs quantum well lattice, highlighting the evolution of collective modes with lattice period.

Findings

Magnetoplasma modes are observed at large inter-disk distances.

Decreasing inter-disk distance modifies the magnetoplasma dispersion.

Inter-disk coupling influences collective excitation behavior.

Abstract

We investigate the effect of inter-disk coupling on the magnetoplasmon dispersion in a square lattice of two-dimensional electron system (2DES) disks etched from a GaAs quantum well. Using magneto-optical terahertz (THz) spectroscopy, we track the evolution of the collective modes as disk lattice period is systematically reduced, thereby increasing the coupling strength. At large distances, the system exhibits magnetoplasma modes corresponding to individual excitations in disks. As the inter-disk distance decreases, we observe a modification to magnetoplasma dispersion.