Re-entrant magic-angle phenomena in twisted bilayer graphene in integer magnetic fluxes

Abstract

In this work we address the re-entrance of magic-angle phenomena (band flatness and quantum-geometric transport) in twisted bilayer graphene (TBG) subjected to strong magnetic fluxes $\pm {\Phi }_0$, $\pm 2{\Phi }_0$, $\pm 3{\Phi }_0$... (${\Phi }_0=h/e$ is the flux quantum per moiré cell). The moiré translation invariance is restored at the integer fluxes, for which we calculate the TBG band structure using accurate atomistic models with lattice relaxations. Similarly to the zero-flux physics outside the magic angle condition, the reported effect breaks down rapidly with the twist. We conclude that the magic-angle physics re-emerges in high magnetic fields, witnessed by the appearance of flat electronic bands distinct from Landau levels, and manifesting non-trivial quantum geometry. We further discuss the possible flat-band quantum geometric contribution to the superfluid weight in strong magnetic fields (28 T at 1.08${}^{\circ }$ twist), according to Peotta-Törmä mechanism.

arXiv comment5 pages, 5 figures

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Cited by in corpus (6)

• Quantum Metric Induced Phases in Moiré Materials
• Hofstadter Topology with Real Space Invariants and Reentrant Projective Symmetries
• Stability of fractional Chern insulators with a non-Landau level continuum limit
• Double and Quadruple Flat Bands tuned by Alternative magnetic Fluxes in Twisted Bilayer Graphene
• Correlated phases and topological phase transition in twisted bilayer graphene at one quantum of magnetic flux
• Atomistic theory of moiré Hofstadter's butterfly in magic-angle graphene