Dirac semimetals are materials in which the conduction and the valence bands have robust crossing points protected by topology or symmetry. Recently, a new type of Dirac semimetals, so called the Dirac line-node semim...Dirac semimetals are materials in which the conduction and the valence bands have robust crossing points protected by topology or symmetry. Recently, a new type of Dirac semimetals, so called the Dirac line-node semimetals （DLNSs）, have attracted a lot of attention, as they host robust Dirac points along the one-dimensional （1D） lines in the Brillouin zone （BZ）. In this work, using angle-resolved photoemission spectroscopy （ARPES） and first-principles calculations, we systematically investigated the electronic structures of non-symmorphic ZrSiS crystal where we clearly distinguished the surface states from the bulk states. The photon-energy-dependent measurements further prove the existence of Dirac line node along the X-R direction. Remarkably, by in situ surface potassium doping, we clearly observed the different evolutions of the bulk and surface electronic states while proving the robustness of the Dirac line node. Our studies not only reveal the complete electronic structures of ZrSiS, but also demonstrate the method manipulating the electronic structure of the compound.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2017YFA0305400)Chinese Academy of Science–Shanghai Science Research Center(Grant No.CAS-SSRC-YH-2015-01)+2 种基金the National Natural Science Foundation of China(Grant No.11674229)the Engineering and Physical Sciences Research Council Platform(Grant No.EP/M020517/1)the Hefei Science–Center Chinese Academy of Sciences(Grant No.2015HSC-UE013)
文摘Dirac semimetals are materials in which the conduction and the valence bands have robust crossing points protected by topology or symmetry. Recently, a new type of Dirac semimetals, so called the Dirac line-node semimetals （DLNSs）, have attracted a lot of attention, as they host robust Dirac points along the one-dimensional （1D） lines in the Brillouin zone （BZ）. In this work, using angle-resolved photoemission spectroscopy （ARPES） and first-principles calculations, we systematically investigated the electronic structures of non-symmorphic ZrSiS crystal where we clearly distinguished the surface states from the bulk states. The photon-energy-dependent measurements further prove the existence of Dirac line node along the X-R direction. Remarkably, by in situ surface potassium doping, we clearly observed the different evolutions of the bulk and surface electronic states while proving the robustness of the Dirac line node. Our studies not only reveal the complete electronic structures of ZrSiS, but also demonstrate the method manipulating the electronic structure of the compound.
