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arXiv · 2211.15682

Kondo lattice model in magic-angle twisted bilayer graphene

Yang-Zhi Chou·Sankar Das Sarma
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Abstract

We systematically study emergent Kondo lattice models from magic-angle twisted bilayer graphene using the topological heavy fermion representation. At the commensurate fillings, we demonstrate a series of symmetric strongly correlated metallic states driven by the hybridization between a triangular lattice of $SU(8)$ local moments and delocalized fermions. In particular, a (fragile) topological Dirac Kondo semimetal can be realized, providing a potential explanation for the symmetry-preserving correlated state at $\nu=0$. We further investigate the stability of the Dirac Kondo semimetal by constructing a quantum phase diagram showing the interplay between Kondo hybridization and magnetic correlation. The destruction of Kondo hybridization suggests that the magic-angle twisted bilayer graphene may be on the verge of a solid-state quantum simulator for novel magnetic orders on a triangular lattice. Experimental implications are also discussed.

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Yang-Zhi Chou, Sankar Das Sarma. 2022-11-28. Kondo lattice model in magic-angle twisted bilayer graphene. https://doi.org/10.1103/physrevlett.131.026501

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