Topologization of β-antimonene on Bi2Se3 via proximity effects
Kris Holtgrewe, Sanjoy Kr Mahatha, Polina M. Sheverdyaeva, Paolo Moras, R. Flammini, Stefano Colonna, F. Ronci, M. Papagno, A. Barla, L. Petaccia, Ziya S. Aliev, М. Б. Бабанлы, Е. В. Чулков, Simone Sanna, Conor Hogan, C. Carbone
Abstract
Topological surface states usually emerge at the boundary between a topological and a conventional insulator. Their precise physical character and spatial localization depend on the complex interplay between the chemical, structural and electronic properties of the two insulators in contact. Using a lattice-matched heterointerface of single and double bilayers of β-antimonene and bismuth selenide, we perform a comprehensive experimental and theoretical study of the chiral surface states by means of microscopy and spectroscopic measurements complemented by first-principles calculations. We demonstrate that, although β-antimonene is a trivial insulator in its free-standing form, it inherits the unique symmetry-protected spin texture from the substrate via a proximity effect that induces outward migration of the topological state. This "topologization" of β-antimonene is found to be driven by the hybridization of the bands from either side of the interface.