Sublattice effect on topological surface states in complex (SnTe)n>1(Bi2 Te3)m=1 compounds

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).An exotic type of topological spin-helical surface state was found in layered van der Waals bonded (SnTe)n=2,3(Bi2Te3)m=1 compounds which comprise two covalently bonded band inverted sublattices, SnTe and Bi2Te3, within a building block. This topological state demonstrates unusual dispersion within the band gap. The dispersion of the surface state has two linear sections of different slope with a shoulder feature between them. Such a dispersion of the topological surface state enables an effective switch of the velocity of topological carriers by means of applying an external electric field.We acknowledge partial support from the Basque Country Government, Departamento de Educacion, Universidades e Investigacion (Grant No. IT-756-13), the Spanish Ministerio de Ciencia e Innovacion (Grant No. FIS2010-19609-C02-01), the Tomsk State University Academic D.I. Mendeleev Fund Program (Grant No. 8.1.05.2015), the Russian Foundation for Basic Research (Grant No. 13-02-12110-ofi-m) and Saint Petersburg State University (project 11.50.202.2015).Peer Reviewe