2018/07/23 by Dongwook Kim, Seongjin Ahn, Jong Hyun Jung +4 · 7 citations
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #2D Materials and Applications #Band gap #Chemistry #Combinatorics #Condensed matter physics #Crystallography #Electronic band structure #Geometry #Graphene research and applications #Hamiltonian (control theory) #Homogeneous space #Materials science #Mathematics #Physics #Semimetal #Topological Materials and Phenomena #Topology (electrical circuits) #Type (biology) #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevmaterials.2.104203
published in Physical Review Materials 2(10) (American Physical Society) · 14 pages, 9 figure
arxiv created 2018/07/23 · openalex publication_date 2018/10/11 · arxiv updated 2018/10/17 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
Dirac line node (DLN) semimetals are a class of topological semimetals that feature band-crossing lines in momentum space. We study the type-I and type-II classification of DLN semimetals by developing a criterion that determines the type using band velocities. Using first-principles calculations, we also predict that Na3N under an epitaxial tensile strain realizes a type-II DLN semimetal with vanishing spin-orbit coupling, characterized by the Berry phase, which is ℤ2 quantized in the presence of inversion and time-reversal symmetries. The surface energy spectrum is calculated to demonstrate the topological phase and the type-II nature is demonstrated by calculating the band velocities. We also develop a tight-binding model and a low-energy effective Hamiltonian that describe the low-energy electronic structure of strained Na3N. The occurrence of a DLN in Na3N under strain is captured in the optical conductivity, which we propose as a means to experimentally confirm the type-II class of DLN semimetals.