Chiral instabilities & the onset of chiral turbulence in QED plasmas

TL;DR

This paper investigates the development of chiral plasma instabilities and turbulence in QED plasmas through lattice simulations, revealing a three-phase process leading to large-scale magnetic field generation and turbulence.

Contribution

First-principles lattice simulation study of chiral plasma instabilities and turbulence in QED, identifying distinct phases and scaling behaviors.

Findings

Exponential growth and damping rates of magnetic modes during linear instability.

Accelerated helicity transfer leading to turbulence and large-scale magnetic fields.

Determination of spectral exponents and scaling laws in the turbulent regime.

Abstract

We present a first principles study of chiral plasma instabilities and the onset of chiral turbulence in QED plasmas far from equilibrium. By performing classical-statistical lattice simulations of the microscopic theory, we show that the generation of strong helical magnetic fields from a helicity imbalance in the fermion sector proceeds via three distinct phases. During the initial linear instability regime the helicity imbalance of the fermion sector causes an exponential growth(damping) of magnetic field modes with right(left) handed polarization, for which we extract the characteristic growth (damping) rates. Secondary growth of unstable modes accelerates the helicity transfer from fermions to gauge fields and ultimately leads to the emergence of a self-similar scaling regime characteristic of decaying turbulence, where magnetic helicity is efficiently transferred to macroscopic length scales. Within this turbulent regime the evolution of magnetic helicity spectrum can be described by an infrared power-spectrum with spectral exponent $\kappa$ and dynamical scaling exponents $\alpha,\beta$, which we determine from our simulations.