• 文献标题:   Hybrid nodal chain in an orthorhombic graphene network
  • 文献类型:   Article
  • 作  者:   BU K, QIAN YT, WANG JT, WENG HM
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:  
  • 被引频次:   6
  • DOI:   10.1103/PhysRevB.103.L081108
  • 出版年:   2021

▎ 摘  要

A topological nodal line (NL) semimetal is a kind of special three-dimensional semimetal state with only nodal lines around the Fermi level. It has been revealed that there are basically two types of NLs when spin-orbit coupling is not considered for electronic system: One is dubbed s-NLs, protected by a combinational symmetry S of spatial inversion (P) and time reversal (T), i.e., S = PT ; the other one is m-NLs, protected by mirror (M) or glide symmetry, constraining the NL inside certain symmetrical planes. However, a hybrid nodal chain (HNC), composed of linked s-NLs and m-NLs from the same two crossing bands, has not been well studied so far. Here, we identify by ab initio calculations a new all-sp(2) hybridized carbon allotrope as a good candidate, which has a unit cell of 24 carbon atoms with Pnna (D-2h(6)) symmetry and is termed oP-C-24 carbon. The HNC hosted by oP-C-24 can be simply described by a two-band k . p model, distinguished from the three-band model proposed for another HNC candidate in the TiRhAs family. This kind of HNC is proposed in a real material here and paves the way for further theoretical and experimental investigations.