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Crystalline Sb 2 Te 3 : Side Surfaces and Disappearance of Dirac Cones
Author(s) -
Kolobov Alexander V.,
Fons Paul,
Saito Yuta
Publication year - 2021
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.202000418
Subject(s) - topological insulator , planar , surface (topology) , surface states , metal , dirac (video compression format) , condensed matter physics , materials science , insulator (electricity) , ab initio , ab initio quantum chemistry methods , chemistry , physics , geometry , quantum mechanics , optoelectronics , mathematics , molecule , computer graphics (images) , computer science , neutrino , metallurgy
Sb 2 Te 3 is an end point of quasibinary GeTe–Sb 2 Te 3 phase‐change alloys and also a prototypical topological insulator (TI). TIs are materials that behave like insulators in their interior but whose surfaces are characterized by metallic states with linear dispersion, the so‐called Dirac cones. Such surface states are symmetry protected, robust, and are maintained even in the presence of surface defects. It has been tacitly implied that any surfaces of a TI possess this property. Herein, using ab initio simulations, it is demonstrated that cleaving Sb 2 Te 3 along certain side surfaces may lead to the disappearance of Dirac surface states. In particular, it is shown that the (110) surface of the typical TI Sb 2 Te 3 is slightly gapped, whereas the ( 1 1 ¯ 0 ) surface is metallic. The significance and potential benefits of the obtained results for practical applications in planar devices and memory cells are discussed.