Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn
We investigate the electronic band structure and the proximity exchange effect in bilayer graphene (BLG) on a family of ferromagnetic multilayers Cr _2 X _2 Te _6 , X = Ge, Si, and Sn, with first principles methods. In each case the intrinsic electric field of the heterostructure induces an orbital...
| Auteurs principaux: | , , |
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| Format: | Article |
| Langue: | English |
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IOP Publishing
2018-01-01
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| Collection: | New Journal of Physics |
| Sujets: | |
| Accès en ligne: | https://doi.org/10.1088/1367-2630/aace51 |
| _version_ | 1827873371701903360 |
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| author | Klaus Zollner Martin Gmitra Jaroslav Fabian |
| author_facet | Klaus Zollner Martin Gmitra Jaroslav Fabian |
| author_sort | Klaus Zollner |
| collection | DOAJ |
| description | We investigate the electronic band structure and the proximity exchange effect in bilayer graphene (BLG) on a family of ferromagnetic multilayers Cr _2 X _2 Te _6 , X = Ge, Si, and Sn, with first principles methods. In each case the intrinsic electric field of the heterostructure induces an orbital gap on the order of 10 meV in the graphene bilayer. The proximity exchange is strongly band-dependent. For example, in the case of Cr _2 Ge _2 Te _6 , the low energy valence band of BLG has exchange splitting of 8 meV, while the low energy conduction band’s splitting is 30 times less (0.3 meV). This striking discrepancy stems from the layer-dependent hybridization with the ferromagnetic substrate. Remarkably, applying a vertical electric field of a few V nm ^–1 reverses the exchange, allowing us to effectively turn ON and OFF proximity magnetism in BLG. Such a field-effect should be generic for van der Waals bilayers on ferromagnetic insulators, opening new possibilities for spin-based devices. |
| first_indexed | 2024-03-12T16:36:04Z |
| format | Article |
| id | doaj.art-032e6f17783d48c7a0f33593b6d39df6 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:36:04Z |
| publishDate | 2018-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-032e6f17783d48c7a0f33593b6d39df62023-08-08T14:52:06ZengIOP PublishingNew Journal of Physics1367-26302018-01-0120707300710.1088/1367-2630/aace51Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and SnKlaus Zollner0https://orcid.org/0000-0002-6239-3271Martin Gmitra1https://orcid.org/0000-0003-1118-3028Jaroslav Fabian2https://orcid.org/0000-0002-3009-4525Institute for Theoretical Physics, University of Regensburg , D-93040 Regensburg, GermanyInstitute for Theoretical Physics, University of Regensburg , D-93040 Regensburg, Germany; Institute of Physics, P. J. Šafárik University in Košice , 040 01 Košice, SlovakiaInstitute for Theoretical Physics, University of Regensburg , D-93040 Regensburg, GermanyWe investigate the electronic band structure and the proximity exchange effect in bilayer graphene (BLG) on a family of ferromagnetic multilayers Cr _2 X _2 Te _6 , X = Ge, Si, and Sn, with first principles methods. In each case the intrinsic electric field of the heterostructure induces an orbital gap on the order of 10 meV in the graphene bilayer. The proximity exchange is strongly band-dependent. For example, in the case of Cr _2 Ge _2 Te _6 , the low energy valence band of BLG has exchange splitting of 8 meV, while the low energy conduction band’s splitting is 30 times less (0.3 meV). This striking discrepancy stems from the layer-dependent hybridization with the ferromagnetic substrate. Remarkably, applying a vertical electric field of a few V nm ^–1 reverses the exchange, allowing us to effectively turn ON and OFF proximity magnetism in BLG. Such a field-effect should be generic for van der Waals bilayers on ferromagnetic insulators, opening new possibilities for spin-based devices.https://doi.org/10.1088/1367-2630/aace51graphenespintronicsheterostructuresproximity exchange |
| spellingShingle | Klaus Zollner Martin Gmitra Jaroslav Fabian Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn New Journal of Physics graphene spintronics heterostructures proximity exchange |
| title | Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn |
| title_full | Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn |
| title_fullStr | Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn |
| title_full_unstemmed | Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn |
| title_short | Electrically tunable exchange splitting in bilayer graphene on monolayer Cr2X2Te6 with X = Ge, Si, and Sn |
| title_sort | electrically tunable exchange splitting in bilayer graphene on monolayer cr2x2te6 with x ge si and sn |
| topic | graphene spintronics heterostructures proximity exchange |
| url | https://doi.org/10.1088/1367-2630/aace51 |
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