Fig. 1: Crystal structure and schematics.
a Crystal structure of 1T-TiSe2 and location of Pt when substituted. b Schematic band structure of 1T-TiSe2 with a valence band at the Γ point and a conduction band at the L point. The dashed lines indicate shadow bands due to CDW formation. The as-grown sample is self-doped with the chemical potential within the conduction band. The solid horizontal lines represent the chemical potential for the “pristine” system within the gap and the “self-doped” system within the conduction band. c Pt substitution for Ti in 1T-TiSe2 creates domain walls between different charge density wave (CDW) ordered domains. The CDW with ordering wavevector q = L supports at least four types of domains in-plane, related to each other by lattice translations. (Form factor of the CDW may introduce additional types of domains. See, e.g., ref. 73.) d, e Schematic local density of states based on scanning tunneling spectroscopy results shown in Fig. 4g inside a CDW domain (d), showing the semiconducting gap of the pristine 1T-TiSe2 band structure, and on a CDW domain wall (e), showing a pseudogap with power-law behavior.
