TY - JOUR
T1 - Topological nodal-line semimetals in alkaline-earth stannides, germanides, and silicides
AU - Huang, Huaqing
AU - Liu, Jianpeng
AU - Vanderbilt, David
AU - Duan, Wenhui
N1 - Funding Information:
We thank Professor Hongbin Zhang and Professor Feng Liu for valuable discussions and fruitful suggestions. H.H. and W.D. are supported by the Ministry of Science and Technology of China and the National Natural Science Foundation of China (Grant No. 11334006). D.V. is supported by NSF Grant No. DMR-14-08838. J.L. would like to acknowledge the support from DMR-14-08838 and DMR-15-06119.
Publisher Copyright:
© 2016 American Physical Society.
PY - 2016/5/26
Y1 - 2016/5/26
N2 - Based on first-principles calculations and an effective Hamiltonian analysis, we systematically investigate the electronic and topological properties of alkaline-earth compounds AX2 (A=Ca, Sr, Ba; X=Si, Ge, Sn). Taking BaSn2 as an example, we find that when spin-orbit coupling is ignored, these materials are three-dimensional topological nodal-line semimetals characterized by a snakelike nodal loop in three-dimensional momentum space. Drumheadlike surface states emerge either inside or outside the loop circle on the (001) surface depending on surface termination, while complicated double-drumhead-like surface states appear on the (010) surface. When spin-orbit coupling is included, the nodal line is gapped and the system becomes a topological insulator with Z2 topological invariants (1;001). Since spin-orbit coupling effects are weak in light elements, the nodal-line semimetal phase is expected to be achievable in some alkaline-earth germanides and silicides.
AB - Based on first-principles calculations and an effective Hamiltonian analysis, we systematically investigate the electronic and topological properties of alkaline-earth compounds AX2 (A=Ca, Sr, Ba; X=Si, Ge, Sn). Taking BaSn2 as an example, we find that when spin-orbit coupling is ignored, these materials are three-dimensional topological nodal-line semimetals characterized by a snakelike nodal loop in three-dimensional momentum space. Drumheadlike surface states emerge either inside or outside the loop circle on the (001) surface depending on surface termination, while complicated double-drumhead-like surface states appear on the (010) surface. When spin-orbit coupling is included, the nodal line is gapped and the system becomes a topological insulator with Z2 topological invariants (1;001). Since spin-orbit coupling effects are weak in light elements, the nodal-line semimetal phase is expected to be achievable in some alkaline-earth germanides and silicides.
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U2 - 10.1103/PhysRevB.93.201114
DO - 10.1103/PhysRevB.93.201114
M3 - Article
AN - SCOPUS:84971015016
VL - 93
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 20
M1 - 201114
ER -