Počet záznamů: 1
Coexistence of Van Hove singularities and pseudomagnetic fields in modulated graphene bilayer
- 1.0534510 - ÚFCH JH 2021 RIV GB eng J - Článek v odborném periodiku
Vejpravová, J. - Pacáková, B. - Dresselhaus, M. S. - Kong, J. - Kalbáč, Martin
Coexistence of Van Hove singularities and pseudomagnetic fields in modulated graphene bilayer.
Nanotechnology. Roč. 31, č. 16 (2020), č. článku 165705. ISSN 0957-4484. E-ISSN 1361-6528
Grant CEP: GA ČR GA18-20357S
GRANT EU: European Commission(XE) 716265
Institucionální podpora: RVO:61388955
Klíčová slova: raman-spectroscopy * biaxial strain * magic-angle * nanoparticles * electron * wrinkles * modulated graphene bilayer * Raman spectroscopy * isotope labeling * Van Hove singularity * pseudomagnetic field
Obor OECD: Physical chemistry
Impakt faktor: 3.874, rok: 2020
Způsob publikování: Omezený přístup
The stacking and bending of graphene are trivial but extremely powerful agents of control over graphene's manifold physics. By changing the twist angle, one can drive the system over a plethora of exotic states via strong electron correlation, thanks to the moire superlattice potentials, while the periodic or triaxial strains induce discretization of the band structure into Landau levels without the need for an external magnetic field. We fabricated a hybrid system comprising both the stacking and bending tuning knobs. We have grown the graphene monolayers by chemical vapor deposition, using C-12 and C-13 precursors, which enabled us to individually address the layers through Raman spectroscopy mapping. We achieved the long-range spatial modulation by sculpturing the top layer (C-13) over uniform magnetic nanoparticles (NPs) deposited on the bottom layer (C-12). An atomic force microscopy study revealed that the top layer tends to relax into pyramidal corrugations with C-3 axial symmetry at the position of the NPs, which have been widely reported as a source of large pseudomagnetic fields (PMFs) in graphene monolayers. The modulated graphene bilayer (MGBL) also contains a few micrometer large domains, with the twist angle similar to 10 degrees, which were identified via extreme enhancement of the Raman intensity of the G-mode due to formation of van Hove singularities (VHSs). We thereby conclude that the twist-induced VHSs coexist with the PMFs generated in the strained pyramidal objects without mutual disturbance. The graphene bilayer modulated with magnetic NPs is a non-trivial hybrid system that accommodates features of twist-induced VHSs and PMFs in environs of giant classical spins.
Trvalý link: http://hdl.handle.net/11104/0312696
Název souboru Staženo Velikost Komentář Verze Přístup 0534510.pdf 1 1.5 MB Vydavatelský postprint vyžádat 0534510preprint.pdf 0 843.9 KB Autorský preprint povolen
Počet záznamů: 1