Wang Meng-Hui, Wang Zhengxuan, Wang Guangtao, Song Haolin, Fu Yuhao, Li Lu, Cui Zhong-Hua
Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
College of Physics, Henan Normal University, Xinxiang, Henan 453007, China.
Nano Lett. 2024 Sep 25;24(38):11831-11838. doi: 10.1021/acs.nanolett.4c02497. Epub 2024 Sep 16.
Topological superconductors (TSCs) offer a promising avenue for delving into exotic states of matter and fundamental physics. We propose a strategy for realizing high transition temperatures (high-) in TSCs by leveraging nontrivial topology alongside a high carrier density near the Fermi level in metal-doped borophenes. We identified 39 candidates with exceptional thermodynamic stability from thousands of Be-intercalated borophenes (BeB) via extensive structural searches. Seven candidates exhibit high carrier densities, with BBeB emerging as a particularly promising candidate. This nanosheet displays both type-I and type-II Dirac fermions, indicative of topological metals, thereby positioning it as an ideal platform for high- TSCs. The high-density π electrons of BBeB originating from type-II Dirac fermions, coupled with the out-of-plane vibrations of B and Be atoms, significantly enhance the electron-phonon coupling (λ = 1.42), resulting in a substantially high- of 31.5 K. These findings underscore the potential of metal-doped borophenes as a cutting-edge material platform for achieving high- TSCs.
拓扑超导体（TSCs）为探索奇异的物质状态和基础物理学提供了一条很有前景的途径。我们提出了一种策略，通过利用非平凡拓扑结构以及金属掺杂硼烯中费米能级附近的高载流子密度，来实现拓扑超导体中的高转变温度（高Tc）。通过广泛的结构搜索，我们从数千种铍插层硼烯（BeB）中识别出39种具有非凡热力学稳定性的候选材料。七种候选材料表现出高载流子密度，其中BBeB成为特别有前景的候选材料。这种纳米片同时展现出I型和II型狄拉克费米子，这是拓扑金属的特征，因此使其成为高Tc拓扑超导体的理想平台。BBeB中源自II型狄拉克费米子的高密度π电子，与硼和铍原子的面外振动相结合，显著增强了电子 - 声子耦合（λ = 1.42），从而产生了高达31.5 K的转变温度。这些发现强调了金属掺杂硼烯作为实现高Tc拓扑超导体的前沿材料平台的潜力。
