Impact of Ultrathin Pb Films on the Topological Surface and Quantum-Well States of Bi2Se3 and Sb2Te3 Topological Insulators

The effect of an ultrathin Pb film deposited on the surface of Bi2Se3 and Sb2Te3 compounds on the electronic state structure of topological insulators is studied experimentally by the angle-resolved photoemission spectroscopy (ARPES) technique. The following features are revealed: formation of two-dimensional quantum-well states in the near-surface region, an increase in the binding energy of the Dirac cone and the core levels, and a simultaneous electronic states intensity redistribution in the system in photoemission spectra. The results obtained show that topological states may coexist at the interface between studied materials and a superconductor, which seems to be promising for application in quantum computers.