Intrinsic quantized anomalous Hall effect in a moiré heterostructure
Serlin, Marec et al. (2020), Intrinsic quantized anomalous Hall effect in a moiré heterostructure, Dryad, Dataset, https://doi.org/10.5061/dryad.ffbg79cqk
The quantum anomalous Hall (QAH) effect combines topology and magnetism to produce precisely quantized Hall resistance at zero magnetic field. We report the observation of a QAH effect in twisted bilayer graphene aligned to hexagonal boron nitride. The effect is driven by intrinsic strong interactions, which polarize the electrons into a single spin and valley resolved moiré miniband with Chern number C = 1. In contrast to magnetically doped systems, the measured transport energy gap is larger than the Curie temperature for magnetic ordering, and quantization to within 0.1% of the von Klitzing constant persists to temperatures of several kelvin at zero magnetic field. Electrical currents as small as 1 nanoampere controllably switch the magnetic order between states of opposite polarization, forming an electrically rewritable magnetic memory.
U.S. Department of Energy, Award: DE-FG02-08ER46524
Air Force Office of Scientific Research, Award: FA9550-16-1-0252
Army Research Office, Award: W911NF-17-1-0323