Topological and nodal superconductor kagome magnesium triboride

Yipeng An, Juncai Chen, Zhengxuan Wang, Jie Li, Shijing Gong, Chunlan Ma, Tianxing Wang, Zhaoyong Jiao, Ruqian Wu, Jiangping Hu, and Wuming Liu

Phys. Rev. Materials 7, 014205 – Published 27 January 2023

Abstract

Recently the kagome compounds have inspired enormous interest and made some great progress such as in the field of superconductivity and topology. Here we predict a different kagome magnesium triboride $(Mg B_{3})$ superconductor with a calculated $T_{c} \sim 12.2 K$ and $T_{c} \sim 15.4$ K by external stress, the potentially highest among the reported diverse kagome-type superconductors. We reveal its various exotic physical properties including the van Hove singularity, flat-band, multiple Dirac points, and nontrivial topology. The system can be described by a two-band model with highly anisotropic superconducting gaps on Fermi surfaces. Its topological and nodal superconducting nature is unveiled by a recently developed symmetry indicators method. Our results suggest that $Mg B_{3}$ can be a new platform to study exotic physics in the kagome structure, and pave a way to seek for more superconductors and topological materials with $X Y_{3} − type$ kagome lattice.

Received 25 July 2022
Revised 2 November 2022
Accepted 6 January 2023

DOI:https://doi.org/10.1103/PhysRevMaterials.7.014205

Physics Subject Headings (PhySH)

First-principles calculations Superconductivity

Kagome lattice Topological materials

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Yipeng An ^1,*, Juncai Chen ¹, Zhengxuan Wang¹, Jie Li ², Shijing Gong³, Chunlan Ma⁴, Tianxing Wang¹, Zhaoyong Jiao¹, Ruqian Wu^2,†, Jiangping Hu^5,6,‡, and Wuming Liu ^5,§

¹School of Physics, Henan Normal University, Xinxiang 453007, China
²Department of Physics and Astronomy, University of California, Irvine 92697, USA
³Department of Physics, East China Normal University, Shanghai 200062, China
⁴School of Physics and Technology, Suzhou University of Science and Technology, Suzhou 215009, China
⁵Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
⁶Kavli Institute of Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China