Cascade of transitions in twisted and non-twisted graphene layers within the van Hove scenario
نویسندگان
چکیده
Abstract Motivated by measurements of compressibility and STM spectra in twisted bilayer graphene, we analyze the pattern symmetry breaking for itinerant fermions near a van Hove singularity. Making use an approximate SU(4) Landau functional, show that structure spin/isospin order parameter changes with increasing filling via cascade transitions. We compute feedback from different orders on argue each splits initially 4-fold degenerate peak particular fashion, consistent data measurements, providing unified interpretation transitions graphene. Our results follow generic analysis SU(4)-symmetric functional are valid beyond specific underlying fermionic model. analogous scenario explains phase non-twisted Bernal rhombohedral trilayer
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ژورنال
عنوان ژورنال: npj quantum materials
سال: 2022
ISSN: ['2397-4648']
DOI: https://doi.org/10.1038/s41535-022-00520-z