Multi-loop node line states in ternary MgSrSi-type crystals  

作　　者：Jinling Lian Lixian Yu Qi-Feng Liang Jian Zhou Rui Yu Hongming Weng 

机构地区：[1]Department of Physics,Shaoxing University,312000 Shaoxing,China [2]National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering,Nanjing University,210093 Nanjing,China [3]School of Physics and Technology,Wuhan University,430072 Wuhan,China [4]Beijing National Laboratory for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,100190 Beijing,China [5]Songshan Lake Materials Laboratory,Guangdong 523808,China

出　　处：《npj Computational Materials》2019年第1期1056-1062,共7页计算材料学（英文）

基　　金：The work is supported by National Natural Science Foundation of China(NSFC)(Grants No.11574215,No.11575116,No.11274359,and No.11422428);H.M.W is also supported by the National 973 program of China(Grants No.2018YFA0305700 and No.2013CB921700);the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB07020100).

摘　　要：Node line band-touchings protected by mirror symmetry(named as m-NLs),the product of inversion and time reversal symmetry S=PT(named as s-NLs),or nonsymmorphic symmetry are nontrivial topological objects of topological semimetals in the Brillouin Zone.In this work,we screened a family of MgSrSi-type crystals using first principles calculations,and discovered that more than 70 members are node-line semimetals.A new type of multi-loop structure was found in AsRhTi that a s-NL touches robustly with a m-NL at some“nexus point”,and in the meanwhile a second m-NL crosses with the s-NL to form a Hopf-link.Unlike the previously proposed Hopf-link formed by two s-NLs or two m-NLs,a Hopf-link formed by a s-NL and a m-NL requires a minimal three-band model to characterize its essential electronic structure.The associated topological surface states on different surfaces of AsRhTi crystal were also obtained.Even more complicated and exotic multi-loop structure of NLs were predicted in AsFeNb and PNiNb.Our work may shed light on search for exotic multi-loop node-line semimetals in real materials.

关 键 词：structure materials TOPOLOGICAL 

分 类 号：O46[理学—电子物理学]