▎ 摘 要
Twisted bilayer graphene (TBG) with interlayer twist angles near the magic angle approximate to 1.08 degrees hosts flat bands and exhibits correlated states including Mott-like insulators, superconductivity, and magnetism. A linear-intemperature normal state resistivity in TBG has been attributed to an exotic Planckian dissipation mechanism but can be equally well explained in terms of conventional electron-phonon scattering. To address this issue, we perform combined temperature-dependent transport measurements of both the longitudinal and Hall resistivities in near-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) proportional to 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.