Ambient-Pressure Anisotropic Single-Gap Superconductivity in La-Trapped B_(26)Cages with Superior Hardness  

作　　者：Haoqi Chen Yushan Tang Haowen Jiang Xuehui Jiang Jialin Wang Chengyao Zhang Defang Duan Yanbin Ma Jing Dong 陈浩琦;唐玉山;姜皓文;姜雪辉;王佳琳;张铖瑶;段德芳;马艳斌;董晶(School of Science,Harbin University of Science and Technology,Harbin 150080,China;School of Science,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China;College of Physics,Jilin University,Changchun 130012,China;School of Public Health,Mudanjiang Medical University,Mudanjiang 157011,China)

机构地区：[1]School of Science,Harbin University of Science and Technology,Harbin 150080,China [2]School of Science,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China [3]College of Physics,Jilin University,Changchun 130012,China [4]School of Public Health,Mudanjiang Medical University,Mudanjiang 157011,China

出　　处：《Chinese Physics Letters》2025年第1期177-191,共15页中国物理快报(英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11904067,12122405,52072188,12274169;51632002)。

摘　　要：Recently,a breakthrough in the high-pressure synthesis of sp^(3)-bonded clathrate-like R-3m-L_(a)B_(8)featuring Latrapped B_(26)cages was achieved.Although the superconducting critical temperature(T_(c))and Vickers hardness(H_(v))of L_(a)B_(8)were estimated,the anisotropic superconductivity and superconducting gap nature remain unclear.The stability of pure B_(26)cages under ambient conditions is of interest for exploring the B_(26)hardness and the role of La atoms in the L_(a)B_(8)hardness.By resolving the Allen–Dynes modified Mc Millan equation and the anisotropic Eliashberg equations,it was found that L_(a)B_(8)exhibits anisotropic single-gap superconductivity with T_(c)=19.0~26.5 K,and the superconducting gap anisotropic ratio reaches 48.50%at 5 K.Most significantly,our work fundamentally validated the coupling of B-2p orbitals with the optical double-degenerate E_(g)phonon modes and A_(g)phonon mode from a novel perspective.The H_(v)of B_(26)cages was determined to be 18.6 GPa,which is lower than that of La-trapped B_(26)cages(i.e.,L_(a)B_(8)),indicating that La acts as a hardness enhancer for L_(a)B_(8).

关 键 词：ANISOTROPIC BREAKTHROUGH 

分 类 号：O511[理学—低温物理]