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تسجيل مستخدم جديدStrange metal behavior of the Hall angle in twisted bilayer graphene
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Rui Lyu
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Twisted bilayer graphene (TBG) with interlayer twist angles near the magic angle $approx 1.08^{circ}$ hosts flat bands and exhibits correlated states including Mott-like insulators, superconductivity and magnetism. Here we report combined temperature-dependent transport measurements of the longitudinal and Hall resistivities in close to magic-angle TBG. While the observed longitudinal resistivity follows linear temperature $T$ dependence consistent with previous reports, the Hall resistance shows an anomalous $T$ dependence with the cotangent of the Hall angle cot $Theta{_H} propto T^2$. Boltzmann theory for quasiparticle transport predicts that both the resistivity and cot $Theta{_H}$ should have the same $T$ dependence, contradicting the observed behavior. This failure of quasiparticle-based theories is reminiscent of other correlated strange metals such as cuprates.
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