Nonequilibrium transport and statistics of Schwinger pair production in Weyl semimetals

TL;DR

This paper investigates the non-equilibrium transport phenomena in Weyl semimetals under a sudden electric field, revealing complex current dynamics, pair creation statistics, and the applicability of different theoretical models.

Contribution

It provides a detailed analysis of the time-dependent current, pair creation distribution, and vacuum persistence in Weyl semimetals beyond linear response, connecting high-energy physics concepts with condensed matter.

Findings

Current exhibits nonmonotonic time dependence with initial polarization and later conduction dominance.

Electron-hole pair distribution transitions from Poissonian to Gaussian with increasing perturbation duration.

Finite probability of no pair creation reflects vacuum persistence in high-energy physics.

Abstract

The non-equilibrium dynamics beyond linear response of Weyl semimetals is studied after a sudden switching on of a DC electric field. The resulting current is a nonmonotonic function of time, with an initial quick increase of polarization current followed by a power-law decay. Particle-hole creation \`a la Schwinger dominates for long times when the conduction current takes over the leading role, with the total current increasing again. The conductivity estimated from a dynamical calculation within a Drude picture agrees with the one obtained from Kubo's formula. The full distribution function of electron-hole pairs changes from Poissonian for short perturbations to a Gaussian in the long perturbation (Landau-Zener) regime. The vacuum persistence probability of high energy physics manifests itself in a finite probability of no pair creation and no induced current at all times.