Ubiquitous formation of bulk Dirac cones and topological surface states from a single orbital manifold in transition-metal dichalcogenides
| Autor: | Bahramy, M. S., Clark, O. J., Yang, B. -J., Feng, J., Bawden, L., Riley, J. M., Marković, I., Mazzola, F., Sunko, V., Biswas, D., Cooil, S. P., Jorge, M., Wells, J. W., Leandersson, M., Balasubramanian, T., Fujii, J., Vobornik, I., Rault, J. E., Kim, T. K., Hoesch, M., Okawa, K., Asakawa, M., Sasagawa, T., Eknapakul, T., Meevasana, W., King, P. D. C. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Nature Materials 17, 21-28 (2018) (DOI 10.1038/nmat5031) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/nmat5031 |
| Popis: | Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied properties. They range from metals and superconductors to strongly spin-orbit-coupled semiconductors and charge-density-wave systems, with their single-layer variants one of the most prominent current examples of two-dimensional materials beyond graphene. Their varied ground states largely depend on the transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle- resolved photoemission, we find that these generically host type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics. Comment: 10 pages, 4 figures |
| Databáze: | arXiv |
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