中国物理B ›› 2026, Vol. 35 ›› Issue (5): 57401-057401.doi: 10.1088/1674-1056/ae39d0

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Unveiling the superconducting mechanism and phase stability of LaB2H8 under pressure

Jirun Wu(吴际润)1, Zefang Wang(王泽方)1, Xin Zhong(钟鑫)1,†, and Hanyu Liu(刘寒雨)1,2,3,‡   

  1. 1 Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China;
    2 State Key Laboratory of High Pressure and Superhard Materials, College of Physics, Jilin University, Changchun 130012, China;
    3 International Center of Future Science, Jilin University, Changchun 130012, China
  • 收稿日期:2025-10-30 修回日期:2026-01-13 接受日期:2026-01-19 发布日期:2026-04-29
  • 通讯作者: Xin Zhong,E-mail:zhongxin@calypso.cn;Hanyu Liu,E-mail:hanyuliu@jlu.edu.cn E-mail:zhongxin@calypso.cn;hanyuliu@jlu.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2023YFA1406002 and 2023YFA1608901), the National Natural Science Foundation of China (Grant Nos. 12574012, 12374009, and T2495231), the Program for Jilin University Science and Technology Innovative Research Team (Grant No. 2021TD-05), the Program for Jilin University Computational Interdisciplinary Innovative Platform, the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB33000000), the Fundamental Research Funds for the Central Universities, and computing facilities at the High-Performance Computing Centre of Jilin University, and the Graduate Innovation Fund of Jilin University (Grant No. 2025CX090).

Unveiling the superconducting mechanism and phase stability of LaB2H8 under pressure

Jirun Wu(吴际润)1, Zefang Wang(王泽方)1, Xin Zhong(钟鑫)1,†, and Hanyu Liu(刘寒雨)1,2,3,‡   

  1. 1 Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China;
    2 State Key Laboratory of High Pressure and Superhard Materials, College of Physics, Jilin University, Changchun 130012, China;
    3 International Center of Future Science, Jilin University, Changchun 130012, China
  • Received:2025-10-30 Revised:2026-01-13 Accepted:2026-01-19 Published:2026-04-29
  • Contact: Xin Zhong,E-mail:zhongxin@calypso.cn;Hanyu Liu,E-mail:hanyuliu@jlu.edu.cn E-mail:zhongxin@calypso.cn;hanyuliu@jlu.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2023YFA1406002 and 2023YFA1608901), the National Natural Science Foundation of China (Grant Nos. 12574012, 12374009, and T2495231), the Program for Jilin University Science and Technology Innovative Research Team (Grant No. 2021TD-05), the Program for Jilin University Computational Interdisciplinary Innovative Platform, the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB33000000), the Fundamental Research Funds for the Central Universities, and computing facilities at the High-Performance Computing Centre of Jilin University, and the Graduate Innovation Fund of Jilin University (Grant No. 2025CX090).

摘要: The recent synthesis of the superhydride LaB$_{2}$H$_{8}$, which exhibits a superconducting transition temperature ($T_{\rm c}$) of 106 K at 90 GPa, offers a promising avenue for exploring high-temperature superconductivity. However, the underlying superconducting mechanism remains elusive. Here, we employ first-principles calculations to systematically investigate the electronic structure, lattice dynamics, electron-phonon coupling, and molecular-orbital features of LaB$_{2}$H$_{8}$. Our analysis reveals that the structural stability and metallic conductivity primarily originate from the covalent B-H bonds within the B$_{2}$H$_{8}$ units. Furthermore, we observe a pronounced softening of low-frequency phonons at elevated pressures, which induces strong electron-phonon coupling and serves as the key driving force for superconductivity in this system. This work not only elucidates the superconducting mechanism in LaB$_{2}$H$_{8}$ but also highlights the importance of covalent hydrogen-based motifs in designing new high-$T_{\rm c}$ superconductors.

关键词: first principles calculations, superconductivity, molecular orbitals

Abstract: The recent synthesis of the superhydride LaB$_{2}$H$_{8}$, which exhibits a superconducting transition temperature ($T_{\rm c}$) of 106 K at 90 GPa, offers a promising avenue for exploring high-temperature superconductivity. However, the underlying superconducting mechanism remains elusive. Here, we employ first-principles calculations to systematically investigate the electronic structure, lattice dynamics, electron-phonon coupling, and molecular-orbital features of LaB$_{2}$H$_{8}$. Our analysis reveals that the structural stability and metallic conductivity primarily originate from the covalent B-H bonds within the B$_{2}$H$_{8}$ units. Furthermore, we observe a pronounced softening of low-frequency phonons at elevated pressures, which induces strong electron-phonon coupling and serves as the key driving force for superconductivity in this system. This work not only elucidates the superconducting mechanism in LaB$_{2}$H$_{8}$ but also highlights the importance of covalent hydrogen-based motifs in designing new high-$T_{\rm c}$ superconductors.

Key words: first principles calculations, superconductivity, molecular orbitals

中图分类号:  (Superconductivity phase diagrams)

  • 74.25.Dw
61.50.Ah (Theory of crystal structure, crystal symmetry; calculations and modeling) 62.50.-p (High-pressure effects in solids and liquids)