Crystalline-electromagnetic responses of higher order topological semimetals
Abstract
Previous work has shown that time-reversal symmetric Weyl semimetals with a quadrupolar arrangement of first-order Weyl nodes exhibit a mixed crystalline-electromagnetic response. For systems with higher order Weyl nodes, which are attached to both surface and hinge Fermi arcs, additional phenomena appear on surfaces of codimension , such as electromagnetic responses of the hinges. Here we construct a model possessing a quadrupole of higher order Weyl nodes to study the interplay between higher order topology and mixed crystalline-electromagnetic responses. We show that the higher order nature of the Weyl nodes yields a dipole of Dirac nodes on certain surfaces, leading to a mixed crystalline-electromagnetic \emph{surface} response that binds charge to dislocations and momentum-density to magnetic fields. In addition, we show that the model possesses a bulk quadrupole moment of crystal-momentum that provides a link between the bulk and surface responses of the system.
Keywords
Cite
@article{arxiv.2308.05796,
title = {Crystalline-electromagnetic responses of higher order topological semimetals},
author = {Mark R. Hirsbrunner and Alexander D. Gray and Taylor L. Hughes},
journal= {arXiv preprint arXiv:2308.05796},
year = {2024}
}