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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Quantum geometry of electronic wavefunctions results in fascinatingtopological phenomena. A prominent example is the intrinsic anomalous Halleffect (AHE) in which a Hall voltage arises in the absence of an appliedmagnetic field. The AHE requires a coexistence of Berry curvature andspontaneous time-reversal symmetry breaking. These conditions can be realizedin two-dimensional moir\'e systems with broken $xy$-inversion symmetry($C_{2z}$) that host flat electronic bands. Here, we explore helical trilayergraphene (HTG), three graphene layers twisted sequentially by the same angleforming two misoriented moir\'e patterns. Although HTG is globally$C_{2z}$-symmetric, surprisingly we observe clear signatures of topologicalbands. At a magic angle $\theta_\mathrm{m}\approx 1.8^\circ$, we uncover arobust phase diagram of correlated and magnetic states using magnetotransportmeasurements. Lattice relaxation leads to large periodic domains in which$C_{2z}$ is broken on the moir\'e scale. Each domain harbors flat topologicalbands with valley-contrasting Chern numbers $\pm(1,-2)$. We find correlatedstates at integer electron fillings per moir\'e unit cell $\nu=1,2,3$ andfractional fillings $2/3,7/2$ with the AHE arising at $\nu=1,3$ and $2/3,7/2$.At $\nu=1$, a time-reversal symmetric phase appears beyond a critical electricdisplacement field, indicating a topological phase transition. Finally,hysteresis upon sweeping $\nu$ points to first-order phase transitions across aspatial mosaic of Chern domains separated by a network of topological gaplessedge states. We establish HTG as an important platform that realizes idealconditions for exploring strongly interacting topological phases and, due toits emergent moir\'e-scale symmetries, demonstrates a novel way to engineertopology.

Helical trilayer graphene: a moir\'e platform for strongly-interacting topological bands