Identification of Topological Surface State in PdTe2 Superconductor by Angle-Resolved Photoemission Spectroscopy

【摘要】 High-resolution angle-resolved photoemission measurements are carried out on transition metal dichalcogenide PdTe₂ that is a superconductor with a T_c at 1.7K.Combined with theoretical calculations,we discover for the first time the existence of topologically nontrivial surface state with Dirac cone in PbTe₂ superconductor.It is located at the Brillouin zone center and possesses helical spin texture.Distinct from the usual three-dimensional topological insulators where the Dirac cone of the surface state lies at the Fermi level,the Dirac point of the surface state in PdTe₂ lies deeply below the Fermi level at ¹.75 eV binding energy and is well separated from the bulk states.The identification of topological surface state in PdTe₂ superconductor deeply below the Fermi level provides a unique system to explore new phenomena and properties and opens a door for finding new topological materials in transition metal chalcogenides.更多还原

【Abstract】 High-resolution angle-resolved photoemission measurements are carried out on transition metal dichalcogenide PdTe₂ that is a superconductor with a T_c at 1.7K.Combined with theoretical calculations,we discover for the first time the existence of topologically nontrivial surface state with Dirac cone in PbTe₂ superconductor.It is located at the Brillouin zone center and possesses helical spin texture.Distinct from the usual three-dimensional topological insulators where the Dirac cone of the surface state lies at the Fermi level,the Dirac point of the surface state in PdTe₂ lies deeply below the Fermi level at ¹.75 eV binding energy and is well separated from the bulk states.The identification of topological surface state in PdTe₂ superconductor deeply below the Fermi level provides a unique system to explore new phenomena and properties and opens a door for finding new topological materials in transition metal chalcogenides.更多还原