School of Physics and Optoelectronics, Xiangtan University, Xiangtan, 411105, Hunan, China.
Phys Chem Chem Phys. 2018 Sep 19;20(36):23500-23506. doi: 10.1039/c8cp03874k.
Topological metals/semimetals (TMs) have emerged as a new frontier in the field of quantum materials. A few two-dimensional (2D) boron sheets have been suggested as Dirac materials, however, to date TMs made of three-dimensional (3D) boron structures have not been found. Herein, by means of systematic first principles computations, we discovered that a rather stable 3D boron allotrope, namely 3D-α' boron, is a nodal-chain semimetal. In momentum space, six nodal lines and rings contact each other and form a novel spindle nodal chain. This 3D-α' boron can be formed by stacking 2D wiggle α' boron sheets, which are also nodal-ring semimetals. In addition, our chemical bond analysis revealed that the topological properties of the 3D and 2D boron structures are related to the π bonds between boron atoms, however, the bonding characteristics are different from those in the 2D and 3D carbon structures.
拓扑金属/半导体（TMs）已成为量子材料领域的一个新前沿。已经有一些二维（2D）硼片被认为是狄拉克材料，但迄今为止尚未发现由三维（3D）硼结构制成的 TM。在此，通过系统的第一性原理计算，我们发现了一种相当稳定的 3D 硼同素异形体，即 3D-α'硼，是一种节线链半导体。在动量空间中，六个节线和节环相互接触，形成一种新颖的纺锤节线链。这种 3D-α'硼可以通过堆叠二维摇摆α'硼片来形成，而二维摇摆α'硼片也是节环半导体。此外，我们的化学键分析表明，3D 和 2D 硼结构的拓扑性质与硼原子之间的π键有关，但是，键合特征与 2D 和 3D 碳结构不同。
