A full gap above the Fermi level: the charge density wave of monolayer VS2
In: ISSN: 2041-1723, 2021
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academicJournal
Zugriff:
International audience ; In the standard model of charge density wave (CDW) transitions, the displacement along a single phonon mode lowers the total electronic energy by creating a gap at the Fermi level, making the CDW a metal-insulator transition. Here, using scanning tunneling microscopy and spectroscopy and ab initio calculations, we show that VS2 realizes a CDW which stands out of this standard model. There is a full CDW gap residing in the unoccupied states of monolayer VS2. At the Fermi level, the CDW induces a topological metal-metal (Lifshitz) transition. Non-linear coupling of transverse and longitudinal phonons is essential for the formation of the CDW and the full gap above the Fermi level. Additionally, x-ray magnetic circular dichroism reveals the absence of net magnetization in this phase, pointing to coexisting charge and spin density waves in the ground state. A charge density wave (CDW) normally creates a gap at the Fermi level, inducing a metal-insulator transition. Here, the authors report that a CDW gap resides in the unoccupied states but induces a topological metal-metal transition at the Fermi level in monolayer VS2.
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A full gap above the Fermi level: the charge density wave of monolayer VS2
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Autor/in / Beteiligte Person: | van Efferen, Camiel ; Berges, Jan ; Hall, Joshua ; van Loon, Erik ; Kraus, Stefan ; Schobert, Arne ; Wekking, Tobias ; Huttmann, Felix ; Plaar, Eline ; Rothenbach, Nico ; Ollefs, Katharina ; Arruda, Lucas Machado ; Brookes, Nick ; Schoenhoff, Gunnar ; Kummer, Kurt ; Wende, Heiko ; Wehling, Tim ; Michely, Thomas ; Universität zu Köln = University of Cologne ; Bremen, Universität ; Universität Duisburg-Essen = University of Duisburg-Essen Essen ; Freie Universität Berlin ; European Synchroton Radiation Facility Grenoble (ESRF) ; Universität Hamburg (UHH) |
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Zeitschrift: | ISSN: 2041-1723, 2021 |
Veröffentlichung: | HAL CCSD ; Nature Publishing Group, 2021 |
Medientyp: | academicJournal |
DOI: | 10.1038/s41467-021-27094-x |
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