Theoretical Prediction of Superconductivity in Boron Kagome Monolayer:MB3(M=Be,Ca,Sr)and the Hydrogenated CaB3  

作　　者：杨柳 李牙平 刘浩东 焦娜 倪美燕 路洪艳 张平 C.S.Ting Liu Yang;Ya-Ping Li;Hao-Dong Liu;Na Jiao;Mei-Yan Ni;Hong-Yan Lu;Ping Zhang;C.S.Ting(School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China;Institute of Applied Physics and Computational Mathematics,Beijing 100088,China;Texas Center for Superconductivity and Department of Physics,University of Houston,Houston,Texas 77204,USA)

机构地区：[1]School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165,China [2]Institute of Applied Physics and Computational Mathematics,Beijing 100088,China [3]Texas Center for Superconductivity and Department of Physics,University of Houston,Houston,Texas 77204,USA

出　　处：《Chinese Physics Letters》2023年第1期53-59,共7页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.12074213,11574108,and 12104253);the Major Basic Program of Natural Science Foundation of Shandong Province(Grant No.ZR2021ZD01);the Project of Introduction and Cultivation for Young Innovative Talents in Colleges and Universities of Shandong Province;the Texas Center for Superconductivity at University of Houston,the Robert A.Welch Foundation(Grant No.E-1146)。

摘　　要：Using first-principles calculations, we predict a new type of two-dimensional(2D) boride MB3(M = Be,Ca, Sr), constituted by boron kagome monolayer and the metal atoms adsorbed above the center of the boron hexagons. The band structures show that the three MB3compounds are metallic, thus the possible phononmediated superconductivity is explored. Based on the Eliashberg equation, for BeB3, CaB3, and SrB3, the calculated electron–phonon coupling constants λ are 0.46, 1.09, and 1.33, and the corresponding superconducting transition temperatures Tc are 3.2, 22.4, and 20.9 K, respectively. To explore superconductivity with higher transition temperature, hydrogenation and charge doping are further considered. The hydrogenated CaB3, i.e.,HCaB3, is stable, with the enhanced λ of 1.39 and a higher Tc of 39.3 K. Moreover, with further hole doping at the concentration of 5.8 × 1011hole/cm2, the Tc of HCaB3can be further increased to 44.2 K, exceeding the Mc Millan limit. The predicted MB3and HCaB3provide new platforms for investigating 2D superconductivity in boron kagome lattice since superconductivity based on monolayer boron kagome lattice has not been studied before.

关 键 词：BORON DOPING SUPERCONDUCTIVITY 

分 类 号：TG1[金属学及工艺—金属学]