# Second-order chiral kinetic theory: Chiral magnetic and pseudomagnetic waves

## TL;DR

This paper develops a second-order chiral kinetic theory for Weyl fermions and investigates how electromagnetic and pseudomagnetic fields influence collective excitations, transforming them into plasmons with field-dependent gaps.

## Contribution

It derives a second-order accurate chiral kinetic theory and analyzes the impact of dynamical fields on chiral magnetic and pseudomagnetic waves, revealing their transformation into plasmons.

## Key findings

- Chiral magnetic and pseudomagnetic waves become plasmons with gaps influenced by fields.
- Dynamical electromagnetism modifies the dispersion of collective excitations.
- Gaps receive quadratic corrections in magnetic and pseudomagnetic fields.

## Abstract

The consistent chiral kinetic theory accurate to the second order in electromagnetic and pseudoelectromagnetic fields is derived for a relativistic matter with two Weyl fermions. By making use of such a framework, the properties of longitudinal collective excitations, which include both chiral magnetic and chiral pseudomagnetic waves, are studied. It is shown that the proper treatment of dynamical electromagnetism transforms these gapless waves into chiral (pseudo)magnetic plasmons, whose Langmuir (plasma) gap receives corrections quadratic in both magnetic and pseudomagnetic fields.