Shielding of a moving test charge in a quantum plasma

TL;DR

This paper investigates how a moving test charge's potential behaves in a quantum plasma, revealing enhanced oscillations and altered decay rates at high velocities due to quantum effects.

Contribution

It provides a detailed analysis of the potential of a moving test charge in a quantum plasma using the Lindhard dielectric function, highlighting the impact of quantum recoil and velocity on Friedel oscillations.

Findings

Friedel oscillations are greatly enhanced behind the moving charge at velocities > 0.5 Fermi velocity.

The decay rate of oscillations changes from 1/r^3 to 1/r^2.5 at high velocities.

In the absence of quantum recoil, the potential resembles classical plasma behavior but without Landau damping.

Abstract

The linearized potential of a moving test charge in a one-component fully degenerate fermion plasma is studied using the Lindhard dielectric function. The motion is found to greatly enhance the Friedel oscillations behind the charge, especially for velocities larger than a half of the Fermi velocity, in which case the asymptotic behavior of their amplitude changes from 1/r^3 to 1/r^2.5. In the absence of the quantum recoil (tunneling) the potential reduces to a form similar to that in a classical Maxwellian plasma, with a difference being that the plasma oscillations behind the charge at velocities larger than the Fermi velocity are not Landau-damped.