Atomic and electronic structure of bismuth-bilayer-terminatedBi2Se3(0001) prepared by atomic hydrogen etching

Abstract

A bilayer of bismuth is recognized as a prototype two-dimensional topological insulator. Here we present a simple and well reproducible top-down approach to prepare a flat and well ordered bismuth bilayer with a lateral size of several hundred nanometers on Bi 2 Se 3 (0001). Using scanning tunneling microscopy, surface x-ray diffraction, and Auger electron spectroscopy we show that exposure of Bi 2 Se 3 (0001) to atomic hydrogen completely removes selenium from the top quintuple layer. The band structure of the system, calculated from first principles for the experimentally derived atomic structure, is in excellent agreement with recent photoemission data. Our results open interesting perspectives for the study of topological insulators in general.

Surface alloying and iron selenide formation inFe/Bi2Se3(0001)observed by x-ray absorption fine structure experiments

“…The hallmark of this so-called topological surface state is a helical spin texture that protects surface electrons from backscattering on defects as long as time reversal symmetry is preserved 4,5 . Such a property makes TIs a unique playground for observation of new effects and apart from the pristine TI surfaces [6][7][8][9] , the TIs covered with various overlayers [10][11][12] or adsorbates [13][14][15][16][17][18][19][20] have also been studied intensely.…”

Breaking time-reversal symmetry at the topological insulator surface by metal-organic coordination networks

“…This means that wide band gap TIs [88] with the DP lying in the midgap or close to the conduction band minimum are suitable candidates for deposition of MOCNs aiming at a controlled modification of its electronic properties close to the Fermi level. The former could be obtained by a variation of bulk atomic composition [89,90], while the latter by constructing heterostructures [71,91,92] like the one used in the present work.…”

Адсорбция никеля на поверхности Bi-=SUB=-2-=/SUB=-Se-=SUB=-3-=/SUB=-

“…Введение немагнитных атомов или молекул не приводит к нарушению инверсии по вре-мени, но, тем не менее, может изменить электронную и атомную структуру ТИ [25][26][27][28][29][30][31]. Становится возможным Бычков−Рашба расщепление состояний, сосуществую-щее с конусом Дирака, располагающимся в запрещенной зоне.…”