Research paperTheoreticalNon-Abelian Chern band in rhombohedral graphene multilayersTaketo Uchida, Takuto Kawakami, Mikito KoshinoarXiv·2026·10.1103/6fxy-6drm·arXiv:2508.07366AbstractMoiré flat bands in rhombohedral multilayer graphene provide a platform for exploring interaction-driven topological phases, where a single isolated band often forms a Chern band. However, non-Abelian degenerate Chern bands with internal symmetries such as SU(N) have so far been realized only in highly engineered systems. Here, the authors show that a doubly degenerate non-Abelian Chern band with Chern number |C| = 1 emerges spontaneously at filling ν = 2 in rhombohedral 3-, 4-, and 5-layer graphene, regardless of the presence of an hBN substrate. Using self-consistent Hartree-Fock calculations, they map out phase diagrams as functions of displacement field and electronic periodicity, and analytically demonstrate that the Fock term drives spontaneous symmetry breaking and generates non-Abelian Berry curvature. They further show that this non-Abelian topology is characterized by SU(2) gauge flux threading the noncontractible cycles of the Brillouin zone, leading to a global non-Abelian holonomy.Read more
Rhombohedral trilayer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral four-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral five-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Research paperTheoreticalNon-Abelian Chern band in rhombohedral graphene multilayersTaketo Uchida, Takuto Kawakami, Mikito KoshinoarXiv·2026·10.1103/6fxy-6drm·arXiv:2508.07366AbstractMoiré flat bands in rhombohedral multilayer graphene provide a platform for exploring interaction-driven topological phases, where a single isolated band often forms a Chern band. However, non-Abelian degenerate Chern bands with internal symmetries such as SU(N) have so far been realized only in highly engineered systems. Here, the authors show that a doubly degenerate non-Abelian Chern band with Chern number |C| = 1 emerges spontaneously at filling ν = 2 in rhombohedral 3-, 4-, and 5-layer graphene, regardless of the presence of an hBN substrate. Using self-consistent Hartree-Fock calculations, they map out phase diagrams as functions of displacement field and electronic periodicity, and analytically demonstrate that the Fock term drives spontaneous symmetry breaking and generates non-Abelian Berry curvature. They further show that this non-Abelian topology is characterized by SU(2) gauge flux threading the noncontractible cycles of the Brillouin zone, leading to a global non-Abelian holonomy.Read more
Rhombohedral trilayer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral four-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral five-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Research paperTheoreticalNon-Abelian Chern band in rhombohedral graphene multilayersTaketo Uchida, Takuto Kawakami, Mikito KoshinoarXiv·2026·10.1103/6fxy-6drm·arXiv:2508.07366AbstractMoiré flat bands in rhombohedral multilayer graphene provide a platform for exploring interaction-driven topological phases, where a single isolated band often forms a Chern band. However, non-Abelian degenerate Chern bands with internal symmetries such as SU(N) have so far been realized only in highly engineered systems. Here, the authors show that a doubly degenerate non-Abelian Chern band with Chern number |C| = 1 emerges spontaneously at filling ν = 2 in rhombohedral 3-, 4-, and 5-layer graphene, regardless of the presence of an hBN substrate. Using self-consistent Hartree-Fock calculations, they map out phase diagrams as functions of displacement field and electronic periodicity, and analytically demonstrate that the Fock term drives spontaneous symmetry breaking and generates non-Abelian Berry curvature. They further show that this non-Abelian topology is characterized by SU(2) gauge flux threading the noncontractible cycles of the Brillouin zone, leading to a global non-Abelian holonomy.Read more
Rhombohedral trilayer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral four-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral five-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Research paperTheoreticalNon-Abelian Chern band in rhombohedral graphene multilayersTaketo Uchida, Takuto Kawakami, Mikito KoshinoarXiv·2026·10.1103/6fxy-6drm·arXiv:2508.07366AbstractMoiré flat bands in rhombohedral multilayer graphene provide a platform for exploring interaction-driven topological phases, where a single isolated band often forms a Chern band. However, non-Abelian degenerate Chern bands with internal symmetries such as SU(N) have so far been realized only in highly engineered systems. Here, the authors show that a doubly degenerate non-Abelian Chern band with Chern number |C| = 1 emerges spontaneously at filling ν = 2 in rhombohedral 3-, 4-, and 5-layer graphene, regardless of the presence of an hBN substrate. Using self-consistent Hartree-Fock calculations, they map out phase diagrams as functions of displacement field and electronic periodicity, and analytically demonstrate that the Fock term drives spontaneous symmetry breaking and generates non-Abelian Berry curvature. They further show that this non-Abelian topology is characterized by SU(2) gauge flux threading the noncontractible cycles of the Brillouin zone, leading to a global non-Abelian holonomy.Read more
Rhombohedral trilayer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral four-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
Rhombohedral five-layer graphene aligned with an hBN substrate, modeled in a moiré superlattice/HF framework at filling ν = 2.2 propertiesSimulated Supercell DftCStudied MaterialBNSubstrate / DielectricExpand
