Researchers at the Weizmann Institute of Science, the Barcelona Institute of Science and Technology and the National Institute for Material Science in Tsukuba (Japan) have recently probed a Chern mosaic topology and Berry-curvature magnetism in magic-angle graphene. Their paper, published in Nature Physics, offers new insight about topological disorder that can occur in condensed matter physical systems.
“Magic angle twisted bilayer graphene (MATBG) has drawn a huge amount of interest over the past few years due to its experimentally accessible flat bands, creating a playground of highly correlated physics,” Matan Bocarsly, one of the researchers who carried out the study, told Phys.org, “One such correlated phase observed in transport measurements is the quantum anomalous Hall effect, where topological edge currents are present even in the absence of an applied magnetic field.”
The quantum anomalous Hall effect is a charge transport-related phenomenon, in which a material’s Hall resistance is quantized to the so-called von Klitzing constant. It resembles the so-called integer quantum Hall effect, which Bocarsly and his colleagued had studied extensively in their previous works, particularly in graphene and MATBG.