2019/01/24 by Yan Gao, Weikang Wu, Peng-Jie Guo +4
Materials Science · Physics and Astronomy · #Boron #Boron and Carbon Nanomaterials Research #Diamond #Diamond cubic #Fermion #Graphene research and applications #Hexagonal crystal system #Lattice (music) #Metal #Structural stability #Tetrahedron #Topological Materials and Phenomena #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevmaterials.3.044202
published as Phys. Rev. Materials 3, 044202 (2019) · 7 pages, 5 figures, 1 table
arxiv created 2019/01/24 · openalex created_date 2019/02/21 · openalex publication_date 2019/04/18 · arxiv updated 2019/04/24 · openalex updated_date 2026/08/05
We predict a new three-dimensional boron allotrope based on systematic first-principles electronic structure calculations. This allotrope can be derived by substituting each carbon atom in a hexagonal diamond lattice with a B4 tetrahedron and possesses the same space group P63/mmc as hexagonal diamond, hence it is termed as H-boron. We show that H-boron has good stability and excellent mechanical property. Remarkably, we find that H-boron is a topological metal with rich types of spin-orbit-free emergent fermions, including semi-Dirac fermion, quadratic and linear triple-point fermion, nodal-line fermion, and nodal-surface fermion. We clarify their symmetry protections and characterize them by constructing the corresponding low-energy effective models. Our work not only discovers a new boron allotrope with excellent properties, it also offers a platform to explore interesting physics of new kinds of emergent fermions.