Dirac nodal surfaces and nodal lines in ZrSiS

Abstract

Topological semimetals are characterized by symmetry-protected band crossings, which can be preserved in different dimensions in momentum space, forming zero-dimensional nodal points, one-dimensional nodal lines, or even two-dimensional nodal surfaces. Materials harboring nodal points and nodal lines have been experimentally verified, whereas experimental evidence of nodal surfaces is still lacking. Here, using angle-resolved photoemission spectroscopy (ARPES), we reveal the coexistence of Dirac nodal surfaces and nodal lines in the bulk electronic structures of ZrSiS. As compared with previous ARPES studies on ZrSiS, we obtained pure bulk states, which enable us to extract unambiguously intrinsic information of the bulk nodal surfaces and nodal lines. Our results show that the nodal lines are the only feature near the Fermi level and constitute the whole Fermi surfaces. We not only prove that the low-energy quasiparticles in ZrSiS are contributed entirely by Dirac fermions but also experimentally realize the nodal surface in topological semimetals.

Projective quasiparticle interference of a single scatterer to analyze the electronic band structure of ZrSiS

“…5(c)]. Here the involved bulk bands [49] correspond to the corners of the inner concentric square in Fig. 2(d).…”

Electron-phonon coupling and Kohn anomaly due to floating two-dimensional electronic bands on the surface of ZrSiS

“…Recently a new kind of surface states due to the reduction of bulk nonsymmorphic symmetry was discovered in ZrSiS 43 , which is a candidate of topological nodal arXiv:1910.12339v1 [cond-mat.mtrl-sci] 27 Oct 2019 line semimetal featured by its nontrivial bulk bands [44][45][46][47][48][49] . ZrSiS is considered to be one of the most promising topological materials with potential applications in electronics and spintronics, due to its very large energy range of linear band dispersion 44 , extremely large nonsaturating magnetoresistance and high mobility of charge carriers 46,[50][51][52][53][54] .…”

Research progress on topological nodal line semimetals

“…此外, 当存在滑移面时, 体系 的倒空间也有可能出现一维的节线 [ 3 8 , 6 7 , 6 8 ] . 在材 料方面很多非磁性节线半金属已经被理论和实验所 证实, 例如三维的拓扑节线半金属有Ag 2 BiO 3 [39] , Cu-TeO 3 [69] , X 3 SiTe 6 (X=Ta, Nb) [70] , PbO 2 [71] , IVX 2 (IV=C, Si, Ge, Sn, Pb; X=S, Se, Te) [72] , ZrO [73] , 单质铍 [74] , ZrSiS [75,76] 等; 二维材料有Cu 2 Si [58] [77] . 当不考虑自旋轨道耦合时,…”