Magnetic-field Induced Screening Effect and Collective Excitations

TL;DR

This paper constructs the fermion propagator in a magnetic field, analyzes collective excitations, and identifies two distinct modes: a massive attenuated gauge particle and a zero-sound-like mode.

Contribution

It explicitly derives the fermion propagator in a magnetic field and characterizes the collective excitation spectrum in this context.

Findings

Identification of two collective modes: a massive attenuated gauge particle and a zero-sound-like mode.

Explicit construction of the fermion propagator in the lowest Landau-level approximation.

Analysis of polarization tensor revealing energy and momentum dependence.

Abstract

We explicitly construct the fermion propagator in a magnetic field background B to take the lowest Landau-level approximation. We analyze the energy and momentum dependence in the polarization tensor and discuss the collective excitations. We find there appear two branches of collective modes in one of two transverse gauge particles; one represents a massive and attenuated gauge particle and the other behaves similar to the zero sound at finite density.