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RESEARCH PRODUCT
Prediction of Weak Topological Insulators in Layered Semiconductors
Claudia FelserBinghai YanLukas Müchlersubject
Condensed Matter - Materials ScienceMaterials scienceStrongly Correlated Electrons (cond-mat.str-el)Condensed matter physicsbusiness.industryBand gapMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesGeneral Physics and AstronomyPrimitive cell02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencesCondensed Matter - Strongly Correlated ElectronsSemiconductorTopological insulator0103 physical sciencesTopological orderCondensed Matter::Strongly Correlated ElectronsCharge transfer insulators010306 general physics0210 nano-technologybusinessSurface statesStacking faultdescription
We report the discovery of weak topological insulators by ab initio calculations in a honeycomb lattice. We propose a structure with an odd number of layers in the primitive unit-cell as a prerequisite for forming weak topological insulators. Here, the single-layered KHgSb is the most suitable candidate for its large bulk energy gap of 0.24 eV. Its side surface hosts metallic surface states, forming two anisotropic Dirac cones. Though the stacking of even-layered structures leads to trivial insulators, the structures can host a quantum spin Hall layer with a large bulk gap, if an additional single layer exists as a stacking fault in the crystal. The reported honeycomb compounds can serve as prototypes to aid in the finding of new weak topological insulators in layered small-gap semiconductors.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-06-20 | Physical Review Letters |