# Dynamic current-current susceptibility in 3D Dirac and Weyl semimetals

## TL;DR

This paper analytically investigates the dynamic current-current response in 3D Dirac and Weyl semimetals, revealing how their optical and magnetic properties are affected by external fields and chiral anomaly effects.

## Contribution

It provides an analytical calculation of the wave-vector and frequency dependent response functions, including plasmon dispersion and orbital magnetic susceptibility, highlighting effects of parallel electric and magnetic fields.

## Key findings

- Analytical expressions for current-current response functions.
- Impact of ${f E} imes{f B}$ fields on response functions.
- Potential experimental signatures of chiral anomaly.

## Abstract

We study the linear response of doped three dimensional Dirac and Weyl semimetals to vector potentials, by calculating the wave-vector and frequency dependent current-current response function analytically. The longitudinal part of the dynamic current-current response function is then used to study the plasmon dispersion, and the optical conductivity. The transverse response in the static limit yields the orbital magnetic susceptibility. In a Weyl semimetal, along with the current-current response function, all these quantities are significantly impacted by the presence of parallel electric and magnetic fields (a finite ${\bf E}\cdot{\bf B}$ term), and can be used to experimentally explore the chiral anomaly.

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Source: https://tomesphere.com/paper/1706.09201