2D and 3D topological phases in BiTeX compounds
Abstract
Recently, it was shown that quantum spin Hall insulator (QSHI) phase with a gap wide enough for practical applications can be realized in the ultra thin films constructed from two inversely stacked structural elements of trivial band insulator BiTeI. Here, we study the edge states in the free-standing Bi2Te2I2 sextuple layer (SL) and the electronic structure of the Bi2Te2I2 SL on the natural BiTeI substrate. We show that the topological properties of the Bi2Te2I2 SL on this substrate keep Z2 invariant. We also demonstrate that ultra thin centrosymmetric films constructed in the similar manner but from related material BiTeBr are trivial band insulators up to five-SL film thickness. In contrast to Bi2Te2I2 for which the stacking of nontrivial SLs in 3D limit gives a strong topological insulator (TI) phase, strong TI is realized in 3D Bi2Te2Br2 in spite of the SL is trivial. For the last material of the BiTeX (X=I,Br,Cl) series, BiTeCl, both 2D and 3D centrosymmetric phases are characterized by topologically trivial band structure.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.