The quantum anomalous Hall (QAH) effect can combine topology and magnetism to produce precisely quantized Hall resistance at zero magnetic field (an environment carefully screened from magnetic fields). In a recent report on Science, M. Serlin and an interdisciplinary research team in the Department of Physics, National Institute of Materials Science and the Kavli Institute for Theoretical Physics in the U.S. and Japan detailed the observation of a QAH effect in twisted bilayer graphene aligned to hexagonal boron nitride. They drove the effect via intrinsic strong interactions, which polarized the electrons into a single spin and valley resolved moiré miniband (interference pattern).
Click here for original story, Intrinsic quantized anomalous Hall effect in a moiré heterostructure
Source: Phys.org