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Chemically driven surface effects in polar intermetallic topological insulators A3Bi
I P Rusinov1, P Golub2, I Yu Sklyadneva3
1Tomsk State University, pr. Lenina, 36, Tomsk, 634050, Russia. rusinovip@gmail.com and St. Petersburg State University, Universitetskaya nab., 7/9, St. Petersburg, 199034, Russia.
Physical Chemistry Chemical Physics : PCCP
|October 11, 2018
Summary
Topological insulators like A3Bi exhibit unique surface electronic spectra driven by polar chemical bonding. These findings clarify surface states and their reactivity in complex materials.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid-State Chemistry
Background:
- Topological insulators (TIs) are materials with unique electronic properties.
- Understanding surface states is crucial for TI applications.
- Complex bonding patterns in TIs present challenges in theoretical analysis.
Purpose of the Study:
- To investigate surface electronic spectra and chemical bonding in A3Bi topological insulators.
- To elucidate the relationship between bulk/surface properties and bonding characteristics.
- To explain emergent surface features in electronic spectra.
Main Methods:
- Bader charge analysis for bulk and surface.
- Real-space bonding indicators.
- Maximally localized-Wannier-function technique.
- Ab initio Hamiltonian calculations.
Main Results:
- A3Bi compounds exhibit delocalized, polar chemical bonding.
- Surface electronic spectra are significantly influenced by chemical bonding.
- Surface states are modulated by surface termination and on-site contributions.
- The study provides an interpretation for experimental observations in Na3Bi.
Conclusions:
- Chemical bonding dictates surface electronic features in A3Bi TIs.
- Surface effects in A3Bi are distinct from covalent TIs like HgX.
- These findings are applicable to a broader range of topological materials with similar bonding.
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