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arXiv · 2207.08895

Anomalous Hall metal and fractional Chern insulator in twisted transition metal dichalcogenides

Valentin Crépel·Liang Fu
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Abstract

We predict robust Ising ferromagnetism driven by Coulomb interaction in the metallic phase of twisted transition metal dichalcogenides homobilayers for a range of small twist angles. Due to the presence of spin-valley locking and Chern band, the completely spin polarized state -- a half metal -- has a spin gap and exhibits anomalous Hall effect. We also find that near a magic angle where the Chern band is predicted to be exceptionally flat, the anomalous Hall metal at $1/3$ filling may become unstable at low temperature to a $\sqrt{3}\times\sqrt{3}$ charge density wave, or a fractional Chern insulator.

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Valentin Crépel, Liang Fu. 2022-07-18. Anomalous Hall metal and fractional Chern insulator in twisted transition metal dichalcogenides. https://doi.org/10.1103/physrevb.107.l201109

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