Imaging real-space chiral rotation of flat-band states in helical trilayer graphene.

Ultra-small twist-angle helical trilayer graphene reveals distinct threefold-anisotropic electronic states localized at specific moiré sites in the flat-band regime, with a chiral rotation that varies with energy.

• Why it matters: Flat bands across moiré graphene systems share similar structures but differ in flattening, isolation, and topology, yet the real-space signatures that distinguish their correlated phases remain unclear.
• What they did: Using scanning tunneling microscopy and spectroscopy, the authors map the threefold-anisotropic local density-of-states patterns and compare them across four representative graphene moiré systems, supported by Bistritzer-MacDonald-model simulations.
• The result: The simulations reproduce the pattern orientations across low-energy minibands and link the local density-of-states rotation direction to the structural chirality of helical trilayer graphene, enabling real-space textures to expose intrinsic flat-band disparities.