Origin of two-dimensional electronic states at Si- And Gd-terminated surfaces of GdRh2Si2 (001)
| Autor: | Vyazovskaya, Alexandra Yu., Otrokov, M. M., Koroteev, Yuri M., Kummer, Kurt, Güttler, Monika, Vyalikh, Denis V., Chulkov, Eugene V. |
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| Přispěvatelé: | Tomsk State University, Saint Petersburg State University, Ministerio de Economía y Competitividad (España), Russian Academy of Sciences, Eusko Jaurlaritza, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Vyazovskaya, Alexandra Yu [0000-0002-3117-4500[, Vyazovskaya, Alexandra Yu [0000-0002-3117-4500 |
| Rok vydání: | 2019 |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | We present a first-principles study of the GdRh2Si2(001) surface electronic structure. Two surfaces, Si- and Gd-terminated, are considered. The origin of the two-dimensional (2D) electronic states at both terminations is investigated by tracing the band structure evolution by going from individual Si, Rh, and Gd atomic layers to (non)stoichiometric ultrathin films and, finally, to thicker GdRh2Si2 slabs. We find the conic-like (Dirac-like) resonance state located in the vicinity of the Γ point at the Si termination to form via the Tamm mechanism and explain the reasons for the differences in dispersion and energy position of the resonance states at the Si and Gd terminations. Then, we show how the butterfly-like dispersion of the Shockley state, residing in the bulk projected band gap near the M point, appears due to the interaction of the bands localized in the surface and subsurface Gd-Si-Rh-Si blocks of the Si termination. Also, a giant sign-alternating atomic relaxation near both the Si- and Gd-terminated surfaces is revealed and its effect on the dispersion and energy position of the 2D states is discussed. In this way we shed light on the origin of the 2D states and explain their dispersion seen in angle-resolved photoemission spectroscopy experiments. We acknowledge support by the Academic D. I. Mendeleev Fund Program of Tomsk State University (Project No. 8.1.01.2018), a Saint Petersburg State University grant for scientific investigations (Grant No. 15.61.202.2015), and the Fundamental Research Program of the State Academies of Sciences for 2019–2021 (line of research III.23.2.9). Support by the Basque Departamento de Educacion, UPV/EHU (Grant No. IT-756-13), and Spanish Ministerio de Economia y Competitividad (MINECO Grant No. FIS2016-75862-P) is also acknowledged. We acknowledge financial support from the Spanish Ministry of Economy (MAT-2017-88374-P). The calculations were performed at the Research park of St. Petersburg State University «Computing Center», at the SKIF Cyberia cluster of Tomsk State University, and at Donostia International Physics Center. |
| Databáze: | OpenAIRE |
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