Unveiling the Quantum Textures of Magic-Angle Graphene's Many-Body Wavefunctions
Researchers have used high-resolution scanning tunnelling microscopy to study the wavefunctions of correlated phases in magic-angle twisted bilayer graphene (MATBG). They found distinct broken-symmetry patterns in the wavefunctions of gapped phases, including correlated insulating, pseudogap, and superconducting phases. The researchers introduced a symmetry-based analysis using complex-valued local order parameters, which revealed intricate textures that distinguish the various correlated phases. The observed quantum textures closely match those of the proposed incommensurate Kekulé spiral order in typical MATBG devices, while ultralow-strain samples exhibit local symmetries similar to a time-reversal symmetric intervalley coherent phase. The superconducting state of MATBG also shows strong signatures of intervalley coherence.