Plasmons in a Square of Two-Dimensional Electrons

TL;DR

This study investigates plasmon modes in a square of two-dimensional electrons, revealing mode interactions and developing a theoretical framework to describe their magneto-optical response, advancing understanding of confined 2D electron systems.

Contribution

The paper introduces a new experimental investigation of plasmon modes in square 2D electron systems and develops an analytical theory to describe their magneto-optical behavior.

Findings

Identification of fundamental dipole and quadrupole plasmon modes.

Discovery of strong mode interactions in square geometry.

Theoretical model accurately describes experimental results.

Abstract

Microwave absorption spectra of a single square of two-dimensional electrons (2DES) have been investigated using an optical detection technique. Fundamental dipole and harmonic quadrupole plasmon modes have been identified and compared to those in the disk geometry. In the square-shaped 2DES, a strong interaction is discovered between the neighboring plasmon modes, whereas no such hybridization is observed in the disk-shaped geometry. We establish a rigid theoretical platform to analytically describe the magneto-optical response of confined two-dimensional systems. The developed theory provides a proper description of the obtained experimental results.