Plasma physics in strong-field regimes: theories and simulations

TL;DR

This paper explores theories and simulations of plasma phenomena in strong electromagnetic fields, covering classical, relativistic-quantum, and non-perturbative regimes, with applications in laser pulse compression and quantum effects.

Contribution

It introduces new models and simulation techniques for plasma behavior in extreme fields, including a fluid model for three-wave interactions and a scalar QED plasma model.

Findings

Derived a formula for three-wave interactions in strong magnetic fields.

Confirmed laser pulse compression via magnetic resonances with particle-in-cell simulations.

Unveiled observable quantum corrections to Faraday rotation and cyclotron absorption.

Abstract

In strong electromagnetic fields, unique plasma phenomena and applications emerge, whose description requires recently developed theories and simulations [Y. Shi, Ph.D. thesis, Princeton University (2018)]. In the classical regime, to quantify effects of strong magnetic fields on three-wave interactions, a convenient formula is derived by solving the fluid model to the second order in general geometry. As an application, magnetic resonances are exploited to mediate laser pulse compression, using which higher intensity pulses can be produced in wider frequency ranges, as confirmed by particle-in-cell simulations. In even stronger fields, relativistic-quantum effects become important, and a plasma model based on scalar quantum electrodynamics (QED) is developed, which unveils observable corrections to Faraday rotation and cyclotron absorption in strongly magnetized plasmas. Beyond the perturbative regime, lattice QED is extended as a numerical tool for plasma physics, using which the transition from wakefield acceleration to electron-positron pair production is captured when laser intensity exceeds the Schwinger threshold.