Dirac surface states in magnonic analogs of topological crystalline insulators

TL;DR

This paper introduces magnonic analogs of topological crystalline insulators with Dirac surface states protected by combined symmetries, demonstrating energy flow responses and proposing a real material realization.

Contribution

It presents a theoretical model of topological magnon systems with protected Dirac surface states and suggests a specific magnetic compound for experimental realization.

Findings

Energy current flows due to Dirac surface states with spin-momentum locking

Models demonstrate protection of surface states by combined symmetries

Proposed realization in CrI₃ compound

Abstract

We propose magnonic analogs of topological crystalline insulators which possess Dirac surface states protected by the combined symmetry of time-reversal and half translation. Constructing models of the topological magnon systems, we demonstrate that the energy current flows through the systems in response to an electric field, owing to the Dirac surface states with the spin-momentum locking. We also propose a realization of the magnonic analogs of topological crystalline insulators in a magnetic compound CrI$_{3}$ with a monoclinic structure.