Topological insulators (TIs) are semiconductors with protected electronic surface states that allow dissipation-free transport. TIs are envisioned as ideal materials for
spintronics and quantum computing. In Bi14Rh3I9, the first weak 3D TI, topology presumably arises from stacking of the intermetallic [(Bi4Rh)3I]2þ layers, which are
predicted to be 2D TIs and to possess protected edge-states, separated by topologically trivial [Bi2I8]2+ octahedra chains. In the new layered salt Bi12Rh3Cu2I5, the same intermetallic layers are separated by planar, i.e., only one atom thick, [Cu2I4]2- anions. Density functional theory (DFT)-based calculations show that the compound is a weak 3D TI, characterized by Z2 ¼ ð0; 0001Þ, and that the topological gap is generated by strong spin–orbit coupling (Eg,calc.~ 10 meV). According to a bonding analysis, the copper cations prevent strong coupling between the TI layers. The calculated surface spectral function for a finite-slab geometry shows distinct characteristics for the two terminations of the main crystal faces 〈001〉, viz., [(Bi4Rh)3I]2þ and [Cu2I4]2-. Photoelectron spectroscopy data confirm the calculated band structure. In situ four-point probe measurements indicate a highly anisotropic bulk semiconductor (Eg,exp.¼ 28 meV) with pathindependent metallic conductivity restricted to the surface as well as temperatureindependent
conductivity below 60 K.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:91959 |
| Date | 11 June 2024 |
| Creators | Carrillo-Aravena, Eduardo, Finzel, Kati, Ray, Rajyavardhan, Richter, Manuel, Heider, Tristan, Cojocariu, Iulia, Baranowski, Daniel, Feyer, Vitaliy, Plucinski, Lukasz, Gruschwitz, Markus, Tegenkamp, Christoph, Ruck, Michael |
| Publisher | Wiley-VCH |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1521-3951, 2100447, 10.1002/pssb.202100447, info:eu-repo/grantAgreement/Deutschen Akademischen Austauschdienstes/Becas Chile Conicyt/2017-62170004/, info:eu-repo/grantAgreement/Deutsche Forschungsgemeinschaft/Exzellenzcluster (ExStra)/390534769//EXC 2004: Materie und Licht für Quanteninformation/ML4Q, info:eu-repo/grantAgreement/Deutsche Forschungsgemeinschaft/SPP 1666: Topologische Isolatoren: Materialien - grundlegende Eigenschaften - Strukturen für Bauelemente/PL 712/2-1/, info:eu-repo/grantAgreement/Deutsche Forschungsgemeinschaft/Exzellenzcluster (ExStra)/390858490//EXC 2147: Komplexität und Topologie in Quantenmaterialien/CT.QMAT |
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