Fine Structure of Cyclotron Resonance in a Two-Dimensional Electron System

TL;DR

This paper reveals that cyclotron resonance in high-quality 2D electron systems is a pure resonance with a fine structure caused by plasma relaxation mechanisms, linked to the fine-structure constant.

Contribution

It demonstrates that CR in a 2DES is a pure resonance unaffected by magnetoplasma hybridization, and uncovers the origin of its fine structure.

Findings

CR is a pure resonance in high-quality 2DES.

The fine structure results from plasma relaxation mechanisms.

The phenomenon is connected to the fine-structure constant.

Abstract

It is established that cyclotron resonance (CR) in a high-quality GaAs/AlGaAs two-dimensional electron system (2DES) originates as a \textit{pure} resonance, that does not hybridize with dimensional magnetoplasma excitations. The magnetoplasma resonances form a fine structure of the CR. The observed fine structure of the CR results from the interplay between coherent radiative and incoherent collisional mechanisms of 2D plasma relaxation. We show that the range of 2DES filling factors from which the phenomenon arises is intimately connected to the fundamental fine-structure constant.