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arXiv · 2001.00438

Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals

Sayandip Ghosh·Carsten Timm
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Abstract

Weyl semimetals exhibit exotic Fermi-arc surface states, which strongly affect their electromagnetic properties. We derive analytical expressions for all components of the composite density-spin response tensor for the surfaces states of a Weyl-semimetal model obtained by closing the band gap in a topological insulating state and introducing a time-reversal-symmetry-breaking term. Based on the results, we discuss the electromagnetic susceptibilities, the current response, and other physical effects arising from the density-spin response. We find a magnetoelectric effect caused solely by the Fermi arcs. We also discuss the effect of electron-electron interactions within the random phase approximation and investigate the dispersion of surface plasmons formed by Fermi-arc states. Our work is useful for understanding the electromagnetic and optical properties of the Fermi arcs.

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Sayandip Ghosh, Carsten Timm. 2020-01-02. Dynamical density and spin response of Fermi arcs and their consequences for Weyl semimetals. https://doi.org/10.1103/physrevb.101.165402

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