Symmetry-Protected Ideal Type-II Weyl Phonons in CdTe

作     者：B. W. Xia R. Wang Z. J. Chen Y. J. Zhao H. Xu 

作者机构：Department of Physics and Shenzhen Key Laboratory of Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 People’s Republic of China Department of Physics The Hong Kong University of Science and Technology Clear Water Bay Hong Kong People’s Republic of China Institute for Structure and Function and Department of Physics Chongqing University Chongqing 400044 People’s Republic of China Department of Physics South China University of Technology Guangzhou 510640 People’s Republic of China Center for Quantum Computing Peng Cheng Laboratory Shenzhen 518055 People’s Republic of China 

出 版 物：《Physical Review Letters》 (物理评论快报)

年 卷 期：2019年第123卷第6期

页      面：065501-065501页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：National Natural Science Foundation of China, NSFC, (11334003, 11404159, 11674148, 11847301, 91634106) National Natural Science Foundation of China, NSFC Science, Technology and Innovation Commission of Shenzhen Municipality, (No.ZDSYS20170303165926217) Science, Technology and Innovation Commission of Shenzhen Municipality Fundamental Research Funds for the Central Universities, (2019CDJDWL0005, 2019CDXYWL0029) Fundamental Research Funds for the Central Universities National Science Fund for Distinguished Young Scholars, (2017B030306008) National Science Fund for Distinguished Young Scholars 

主　　题：Acoustic phonons Optical phonons Phonons Symmetry protected topological states Topological phases of matter Topological materials Weyl semimetal k dot p method 

摘      要：Nontrivial low-energy excitations of crystalline solids have insightfully strengthened understanding of elementary particles in quantum field theory. Usually, topological quasiparticles are mainly focused on fermions in topological semimetals. We alternatively show by first-principles calculations and symmetry analysis that ideal type-II Weyl phonons are present in zinc-blende cadmium telluride, a well-known II-VI semiconductor. Importantly, these type-II Weyl phonons originate from the inversion between the longitudinal acoustic and transverse optical branches. Symmetry guarantees that the type-II Weyl points lie along the high-symmetry lines at the boundaries of the Brillouin zone even with a breaking of inversion symmetry, exhibiting the robustness of protected phonon features. The nontrivial phonon surface states and surface arcs projected on the semifinite (001) and (111) surfaces are investigated. The phonon surface arcs connecting the Weyl points with opposite chirality, guaranteed to be very long, are clearly visible. We not only offer a promising candidate for studying type-II Weyl phonons but also provide a route to realize symmetry-protected nontrivial phonons and related applications in realistic materials.