Weyl Point and Nontrivial Surface States in a Helical Topological Material

Meize Li,Xin Zhou,Lianlian Du,Kun Song,Xiaopeng Zhao,Ruonan Ji,Yahong Liu

doi:10.3389/fmats.2021.805862

Abstract

Topological material has been widely studied in recent years because of excellent physical properties. In this paper, a Weyl topological material composed of the double left-handed helixes is presented. It is demonstrated that the proposed structure possesses a two-dimensional complete topological nontrivial bandgap for a fixed kz in the microwave frequency, and the robust surface states are observed. This unique function provides a promising platform for the development of photonics and electromagnetics.

Highlights

Topological materials are an unusual material state, and the most interesting feature is that they can be distinguished strictly from all other materials using a mathematical concept called ‘topology’
It is demonstrated that topological photonics can achieve many interesting phenomena, such as quantum Hall effect (Raghu and Haldane, 2008; Wang et al, 2008; Wang et al, 2009; Ye et al, 2019), quantum anomalous Hall effect (Fang and Wang, 2019; Mittal et al, 2019), quantum spin Hall effect (Christiansen et al, 2019; Slobozhanyuk et al, 2019; Sun et al, 2019; Zhirihin et al, 2019), and quantum valley Hall effect (Han et al, 2021; Jo et al, 2021)
We propose a Weyl topological material composed of double left-handed helixes

Summary

INTRODUCTION

Topological materials are an unusual material state, and the most interesting feature is that they can be distinguished strictly from all other materials using a mathematical concept called ‘topology’. The Weyl topological material has a topological nontrivial bandgap in the bandwidth from 15.55 to 16.45 GHz, where the topologically protected surface state is observed. It can be seen that the topological nontrivial bandgap appears around 16 GHz. We further investigate the electric field distributions of the present topological material to demonstrate the surface state. Due to the limitation of calculation, the selected stepped structure has a small thickness in the x direction, resulting in energy attenuation

CONCLUSION

DATA AVAILABILITY STATEMENT