Nonlinear Quantum Electrodynamics in Dirac materials

TL;DR

This paper demonstrates that Dirac materials exhibit strong nonlinear quantum electrodynamics effects at accessible magnetic fields, enabling exploration of high-field QED phenomena in solid-state systems and predicting novel magneto-electric effects.

Contribution

It reveals that nonlinear QED phenomena occur in Dirac materials at much lower fields than in vacuum, providing a new platform for studying high-field quantum effects and proposing related experiments.

Findings

Strong nonlinearity in Dirac materials at ~1 T

Unified explanation of recent experiments

Prediction of new magneto-electric effects

Abstract

Classical electromagnetism is linear. However, fields can polarize the vacuum Dirac sea, causing quantum nonlinear electromagnetic phenomena, e.g., scattering and splitting of photons, that occur only in very strong fields found in neutron stars or heavy ion colliders.We show that strong nonlinearity arises in Dirac materials at much lower fields $\sim 1\:\text{T}$, allowing us to explore the nonperturbative, extremely high field limit of quantum electrodynamics in solids. We explain recent experiments in a unified framework and predict a new class of nonlinear magneto-electric effects, including a magnetic enhancement of dielectric constant of insulators and a strong electric modulation of magnetization. We propose experiments and discuss the applications in novel materials.