Thermal Fluctuations of the Electric Field in the Presence of Carrier Drift

TL;DR

This paper investigates how steady carrier drift in a semiconductor affects electromagnetic field fluctuations, especially near the plasma frequency, altering plasmon dispersion and impacting near-field evanescent waves.

Contribution

It reveals the significant influence of carrier drift on electromagnetic fluctuations and plasmon dispersion in non-equilibrium semiconductors, a novel insight into fluctuation behavior.

Findings

Carrier drift modifies electromagnetic fluctuation spectra.

Significant effects near the plasma frequency.

Altered dispersion relations for plasmons.

Abstract

We consider a semiconductor in a non-equilibrium steady state, with a dc current. On top of the stationary carrier motion there are fluctuations. It is shown that the stationary motion of the carriers (i.e., their drift) can have a profound effect on the electromagnetic field fluctuations in the bulk of the sample as well as outside it, close to the surface (evanescent waves in the near field). The effect is particularly pronounced near the plasma frequency. This is because drift leads to a significant modification of the dispersion relation for the bulk and surface plasmons.