The electromagnetic response of a relativistic Fermi gas at finite temperatures: applications to condensed-matter systems

TL;DR

This paper analyzes the electromagnetic response of a relativistic Fermi gas at finite temperatures, providing theoretical calculations that align with experimental data and discussing potential applications in plasmonics and photonics.

Contribution

It presents a first-order theoretical model of the electromagnetic response of a relativistic Fermi gas at finite temperatures, connecting it with experimental observations in condensed-matter systems.

Findings

Good agreement with Lindhard dielectric function at low temperatures

Experimental validation with plasmon energy in graphite and tin oxide

Potential relevance for future plasmonic and photonic research

Abstract

We investigate the electromagnetic response of a relativistic Fermi gas at finite temperatures. Our theoretical results are first-order in the fine-structure constant. The electromagnetic permittivity and permeability are introduced via general constitutive relations in reciprocal space, and computed for different values of the gas density and temperature. As expected, the electric permittivity of the relativistic Fermi gas is found in good agreement with the Lindhard dielectric function in the low-temperature limit. Applications to condensed-matter physics are briefly discussed. In particular, theoretical results are in good agreement with experimental measurements of the plasmon energy in graphite and tin oxide, as functions of both the temperature and wave vector. We stress that the present electromagnetic response of a relativistic Fermi gas at finite temperatures could be of potential interest in future plasmonic and photonic investigations.