Intrinsic quantized anomalous Hall effect in a moir\'e heterostructure

Autor: Serlin, M., Tschirhart, C. L., Polshyn, H., Zhang, Y., Zhu, J., Watanabe, K., Taniguchi, T., Balents, L., Young, A. F.
Rok vydání: 2019
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1126/science.aay5533
Popis: We report the observation of a quantum anomalous Hall effect in twisted bilayer graphene showing Hall resistance quantized to within .1\% of the von Klitzing constant $h/e^2$ at zero magnetic field.The effect is driven by intrinsic strong correlations, which polarize the electron system into a single spin and valley resolved moir\'e miniband with Chern number $C=1$. In contrast to extrinsic, magnetically doped systems, the measured transport energy gap $\Delta/k_B\approx 27$~K is larger than the Curie temperature for magnetic ordering $T_C\approx 9$~K, and Hall quantization persists to temperatures of several Kelvin. Remarkably, we find that electrical currents as small as 1~nA can be used to controllably switch the magnetic order between states of opposite polarization, forming an electrically rewritable magnetic memory.
Comment: Additional information available at www.afylab.com
Databáze: arXiv
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