Zeng Shuming, Li Geng, Zhao Yinchang
College of Physics Science and Technology, Yangzhou University, Jiangsu 225009, China.
School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tongyan Road 38, Tianjin 300350, China.
Phys Chem Chem Phys. 2023 Nov 8;25(43):29960-29967. doi: 10.1039/d3cp03485b.
Since a report of superconductivity in elemental boron at high pressure [M. I. Eremets ., , 2001, , 272-274], many efforts have been devoted to the search for superconductivity in diverse boron allotropes. However, there are few superconducting phenomena to be discovered theoretically and experimentally in elemental bulk boron crystals at normal pressure to date. In this paper, we propose a metastable but dynamically stable metallic bulk boron phase within the kagome lattice, and demonstrate from first principles good superconductivity with a high superconducting critical temperature , , ∼34-39 K, in the elemental bulk boron at ambient pressure. Our calculations indicate that such a high- superconductivity is closely related to the Fermi surface displaying strong electron-phonon coupling with a two-region-like distribution feature, which resulted from two different types of covalent bonding crossing the Fermi level and also gives rise to a two-gap-like superconducting nature in the system. We uncover that the strong electron-lattice coupling is dominated by the transversal acoustic phonon modes around a degenerate softening kink that places the system on the verge of a latent charge density wave. The present findings shed light on a study of the high- superconductivity of the elemental bulk boron phase at normal pressure.
自从有关于元素硼在高压下超导性的报道[M. I. 叶列梅茨等人，2001年，第272 - 274页]以来，人们致力于在各种硼的同素异形体中寻找超导性。然而，迄今为止，在常压下的元素块状硼晶体中，从理论和实验上发现的超导现象很少。在本文中，我们提出了一种在 kagome 晶格内亚稳但动态稳定的金属块状硼相，并从第一性原理证明了在常压下的元素块状硼中具有高达超导临界温度(T_c) ∼34 - 39 K的良好超导性。我们的计算表明，这种高超导性与费米面密切相关，费米面显示出具有两区分布特征的强电子 - 声子耦合，这是由两种不同类型的共价键穿过费米能级导致的，并且在系统中产生了类似双能隙的超导性质。我们发现，强电子 - 晶格耦合由围绕简并软化扭结的横向声子模式主导，该扭结使系统处于潜在电荷密度波的边缘。本研究结果为常压下元素块状硼相的高超导性研究提供了线索。
