Dynamical density response and optical conductivity in topological metals

Abstract

Topological metals continue to attract attention as novel gapless states of matter. While there by now exists an exhaustive classification of possible topologically nontrivial metallic states, their observable properties, that follow from the electronic structure topology, are less well understood. Here we present a study of the electromagnetic response of three-dimensional topological metals with Weyl or Dirac nodes in the spectrum, which systematizes and extends earlier pioneering studies. In particular, we argue that a smoking-gun feature of the chiral anomaly in topological metals is the existence of propagating chiral density modes even in the regime of weak magnetic fields. We also demonstrate that the optical conductivity of such metals exhibits an extra peak, which exists on top of the standard metallic Drude peak. The spectral weight of this peak is transferred from high frequencies and its width is proportional to the chiral charge relaxation rate.

10 pages, 2 figures, published version

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Cited by in corpus (9)

• Review of experiments on the chiral anomaly in Dirac-Weyl semimetals
• Rare regions and avoided quantum criticality in disordered Weyl semimetals and superconductors
• Probing charge pumping and relaxation of the chiral anomaly in a Dirac semimetal
• Skin effect as a probe of transport regimes in Weyl semimetals
• Anomalous Electromagnetic Field Penetration in a Weyl or Dirac Semimetal
• Current-Induced Spin Accumulation and Magnetoresistance in Chiral Semimetals
• Topological properties of Dirac and Weyl semimetals
• Electric and chiral response to a pseudoelectric field in Weyl materials
• Chiral charge conservation and ballistic magnetotransport in a disordered Weyl semimetal