Work

Identification of Topological Surface State in PdTe 2 Superconductor by Angle-Resolved Photoemission Spectroscopy

Year: 2015

Type: article

Abstract: High-resolution angle-resolved photoemission measurements are carried out on transition metal dichalcogenide PdTe 2 that is a superconductor with a T c at 1.7 K. Combined with theoretical calculations, we discover for the first time the existence of topologically nontrivial surface state with Dirac cone in PbTe 2 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 PdTe 2 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 PdTe 2 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.

Source: Chinese Physics Letters

DOI: 10.1088/0256-307x/32/6/067303