Related Experiment Video
Updated: Jul 17, 2026

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Fractional high-Chern insulator in twisted rhombohedral graphene
Zexu Li1, Wenxuan Wang2, Fajie Wang1
1International Center for Quantum Materials, School of Physics, Peking University, Beijing, China.
Abstract:
The realization of fractional Chern insulators opens the possibility of exploring fractionally charged excitations1-7 and anyonic statistics8-11 in the absence of a magnetic field. A central question is whether lattice-based systems can give rise to radically new states, distinct from those observed in traditional fractional quantum Hall systems12-20. Here we investigate a type of moiré flat-band system composed of Bernal bilayer graphene and rhombohedral tetralayer graphene. We discover an unprecedented richness of quantum anomalous Hall insulators with Chern numbers from |C| = 1 to |C| = 7 at a moiré filling factor v = 1 and around v = 3. Remarkably, we observe an exotic fractional Chern insulator with C = 7/3 around v = 2/3, which is beyond all known fractional Chern insulators described by either the Jain sequence or current high-Chern theory21-27. Our work expands the understanding of fractionally charged excitations beyond the Landau-level basis and offers a moiré platform for exploring anyons.
Related Concept Videos
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Imperfections in Crystal Structure: Stoichiometric Point Defects
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Hybridization of Atomic Orbitals I
VSEPR Theory and the Effect of Lone Pairs

