Collective excitations of a system of coupled relativistic and non-relativistic two-dimensional electron gases

TL;DR

This paper investigates how interactions between relativistic and non-relativistic electrons in a 2D system influence collective excitations, revealing the impact on plasmon modes and their dispersions.

Contribution

It introduces a detailed analysis of coupled relativistic and non-relativistic electron gases, highlighting the role of inter-species interactions on plasmon behavior.

Findings

Inter-species interaction strength affects the number of plasmon modes.

Inter-species interactions modify plasmon dispersion relations.

The system exhibits different collective excitation regimes based on interaction parameters.

Abstract

We study collective excitations of a two-dimensional electron system consisting of two kinds of charge carriers: relativistic or Dirac electrons with linear dispersion and non-relativistic electrons with parabolic dispersion. We find that the strength of the interaction between the different charge carriers, i.e., the inter-species interaction, plays a significant role in determining the number of plasmon modes as well as their dispersions in certain parameter regimes.