Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111)
The Ir(111) surface is known to host a surface state with a giant spin–orbit splitting due to the Rashba effect. This surface state is stable even in air when Ir is protected with an epitaxial graphene overlayer. In the present paper, we reveal an effect allowing one to tune the binding energy of th...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2013-01-01
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| Series: | New Journal of Physics |
| Online Access: | https://doi.org/10.1088/1367-2630/15/11/115009 |
| _version_ | 1797751719953694720 |
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| author | J Sánchez-Barriga G Bihlmayer D Wortmann D Marchenko O Rader A Varykhalov |
| author_facet | J Sánchez-Barriga G Bihlmayer D Wortmann D Marchenko O Rader A Varykhalov |
| author_sort | J Sánchez-Barriga |
| collection | DOAJ |
| description | The Ir(111) surface is known to host a surface state with a giant spin–orbit splitting due to the Rashba effect. This surface state is stable even in air when Ir is protected with an epitaxial graphene overlayer. In the present paper, we reveal an effect allowing one to tune the binding energy of this spin-split surface state up and down and demonstrate the practical application of this effect by two different approaches. The first approach is related to a decoration of the moiré pattern of single-layer graphene on Ir(111) by self-assembled nanoclusters of different compositions. The clusters locally pin graphene to the Ir substrate and enhance the amplitude of its structural corrugation, which, in turn, leads to an increase in the surface state binding energy. The second approach is related to the synthesis of few-layer graphene on Ir(111) by segregation of carbon. Additional graphene layers induce a shift of the Ir surface state towards lower binding energies and bring it almost to the Fermi level. Based on density functional calculations performed for the graphene/Ir(111) system, we show that in both cases the effect causing the binding energy shifts is intimately related to the distance between graphene and the Ir surface, which is subject to change due to deposition of clusters or by increasing the amount of graphene overlayers. In contrast, the observed spin–orbit splitting of the Ir(111) surface state remains remarkably robust and constant in all cases. Our theoretical analysis reveals that such stability can be explained by the localization properties of the Ir surface state that is a deep surface resonance. |
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| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:52:43Z |
| publishDate | 2013-01-01 |
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| series | New Journal of Physics |
| spelling | doaj.art-7cf4e0df482c43c6b4270696874fc1f92023-08-08T11:05:34ZengIOP PublishingNew Journal of Physics1367-26302013-01-01151111500910.1088/1367-2630/15/11/115009Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111)J Sánchez-Barriga0G Bihlmayer1D Wortmann2D Marchenko3O Rader4A Varykhalov5Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin, GermanyPeter Grünberg Institut and Institute for Advanced Simulation , Forschungszentrum Jülich and JARA, 52425 Jülich, GermanyPeter Grünberg Institut and Institute for Advanced Simulation , Forschungszentrum Jülich and JARA, 52425 Jülich, GermanyHelmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin, GermanyHelmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin, GermanyHelmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin, GermanyThe Ir(111) surface is known to host a surface state with a giant spin–orbit splitting due to the Rashba effect. This surface state is stable even in air when Ir is protected with an epitaxial graphene overlayer. In the present paper, we reveal an effect allowing one to tune the binding energy of this spin-split surface state up and down and demonstrate the practical application of this effect by two different approaches. The first approach is related to a decoration of the moiré pattern of single-layer graphene on Ir(111) by self-assembled nanoclusters of different compositions. The clusters locally pin graphene to the Ir substrate and enhance the amplitude of its structural corrugation, which, in turn, leads to an increase in the surface state binding energy. The second approach is related to the synthesis of few-layer graphene on Ir(111) by segregation of carbon. Additional graphene layers induce a shift of the Ir surface state towards lower binding energies and bring it almost to the Fermi level. Based on density functional calculations performed for the graphene/Ir(111) system, we show that in both cases the effect causing the binding energy shifts is intimately related to the distance between graphene and the Ir surface, which is subject to change due to deposition of clusters or by increasing the amount of graphene overlayers. In contrast, the observed spin–orbit splitting of the Ir(111) surface state remains remarkably robust and constant in all cases. Our theoretical analysis reveals that such stability can be explained by the localization properties of the Ir surface state that is a deep surface resonance.https://doi.org/10.1088/1367-2630/15/11/115009 |
| spellingShingle | J Sánchez-Barriga G Bihlmayer D Wortmann D Marchenko O Rader A Varykhalov Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111) New Journal of Physics |
| title | Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111) |
| title_full | Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111) |
| title_fullStr | Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111) |
| title_full_unstemmed | Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111) |
| title_short | Effect of structural modulation and thickness of a graphene overlayer on the binding energy of the Rashba-type surface state of Ir(111) |
| title_sort | effect of structural modulation and thickness of a graphene overlayer on the binding energy of the rashba type surface state of ir 111 |
| url | https://doi.org/10.1088/1367-2630/15/11/115009 |
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