English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Recently, signatures of quantum anomalous Hall states with spontaneousferromagnetism were observed in twisted bilayer graphenes (TBGs) near 3/4filling [1, 2]. Importantly, it was demon-strated that an extremely smallcurrent can switch the direction of the magnetization. This offers the prospectof realizing low energy dissipation magnetic memories. However, the mechanismof the current-driven magnetization switching is poorly understood as thecharge currents in graphene layers are generally believed to be non-magnetic.In this work, we demonstrate that, in TBGs, the twist-induced reduction oflattice symmetry allows a charge current to generate net orbital magnetizationat a general filling factor through magnetoelectric effects. Substrate-inducedstrain and sublattice symmetry breaking further reduce the symmetry such thatan out-of-plane orbital magnetization can be generated. Due to the largenon-trivial Berry phase of the flat bands, the orbital magnetization of a Blochstate can be as large as tens of Bohr magnetons and therefore a small currentwould be sufficient to generate a large orbital magnetization. We furtherdemonstrate how the charge current with orbital magnetization can switch themagnetization of the quantum anomalous Hall state near 3/4 filling as observedin the experiments [1, 2].

Giant Orbital Magneto-electric effect and Current-driven Magnetization Switching in Twisted Bilayer Graphene