Symmetry-enforced nodal cage phonons in Th2BC2

Wang，Meng1; Wang，Yu1; Yang，Zhiyong1; Fan，Jing2; Zheng，Baobing1,3,4; Wang，Rui3,4,5; Wu，Xiaozhi3,4,5

2022-05-31

10.1103/PhysRevB.105.174309

PHYSICAL REVIEW B   影响因子和分区

2469-9950

2469-9969

Exploring unique topological states in condensed-matter systems has attracted great interest especially for the topological phonons recently. Based on the unbiased structure prediction approach combined with first-principles calculations, the long-sought crystal structure of Th2BC2 is determined. Most importantly, we show by the symmetry analysis and the phonon tight-binding Hamiltonian that Th2BC2 hosts nodal surface phonons on the q(z) = +/-pi plane, coexisting with nodal line phonons on the q(y) = 0 and q(y) = +/-pi planes, consequently, forming cagelike phonons. The nodal surface phonons are protected by the screw axis (C) over tilde (2z), and the nodal line phonons are enforced by inversion and time-reversal symmetries, demonstrated by the codimension argument and the effective model analysis. In addition, we also investigate the phonon surface states and the isofrequency arc on the (100) surface, which benefit the confirmation of the nodal cage phonons in experiments. Our paper not only determines the long-sought crystal structure of Th2BC2, but also provides an ideal candidate to realize the exotic topological phonon excitations.

SCI ; EI

英语

其他

National Natural Science Foundation of China (NSFC)["11974062","12047564","11704177"] ; Natural Science Basic Research Program of Shaanxi[2022JM001] ; Chongqing Natural Science Foundation[cstc2019jcyj-msxmX0563] ; Fundamental Research Funds for the Central Universities of China["2019CDXYWL0029","2020CDJQY-A057"]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000833531600005

AMER PHYSICAL SOC

20222312200753

Calculations ; Crystal structure ; Thorium compounds ; Topology

Mathematics:921 ; Combinatorial Mathematics, Includes Graph Theory, Set Theory:921.4 ; Crystal Lattice:933.1.1

PHYSICS

2-s2.0-85131306621

Web of Science

1.College of Physics and Optoelectronic Technology,Baoji University of Arts and Sciences,Baoji,721016,China
2.Center for Computational Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Institute for Structure and Function,Department of Physics,Chongqing University,Chongqing,400044,China
4.Chongqing Key Laboratory for Strongly Coupled Physics,Chongqing University,Chongqing,400044,China
5.Center of Quantum Materials and Devices,Chongqing University,Chongqing,400044,China

Wang，Meng,Wang，Yu,Yang，Zhiyong,et al. Symmetry-enforced nodal cage phonons in Th2BC2[J]. PHYSICAL REVIEW B,2022,105(17).

Wang，Meng.,Wang，Yu.,Yang，Zhiyong.,Fan，Jing.,Zheng，Baobing.,...&Wu，Xiaozhi.(2022).Symmetry-enforced nodal cage phonons in Th2BC2.PHYSICAL REVIEW B,105(17).

Wang，Meng,et al."Symmetry-enforced nodal cage phonons in Th2BC2".PHYSICAL REVIEW B 105.17(2022).