Deep Insight Into the Electronic Structure of Ternary Topological Insulators: A Comparative Study of PbBi₄Te₇ and PbBi₆Te₁₀

Abstract

By means of angle‐resolved photoemission spectroscopy measurements, the electronic band structure of the three‐dimensional PbBi 4 Te 7 and PbBi 6 Te 10 topological insulators is compared. The measurements clearly reveal coexisting topological and multiple Rashba‐like split states close to the Fermi level for both systems. The observed topological states derive from different surface terminations, as confirmed by scanning tunneling microscopy measurements, and are well‐described by the density functional theory simulations. Both the topological and the Rashba‐like states reveal a prevalent two‐dimensional character barely affected by air exposure. X‐ray and valence band photoemission measurements suggest Rashba‐like states stem from the van der Waals gap expansion, consistently with density functional theory calculations.