论文标题
扭曲的双层石墨烯中大厅角的奇怪金属行为
Strange metal behavior of the Hall angle in twisted bilayer graphene
论文作者
论文摘要
扭曲的双层石墨烯(TBG)在魔法角度附近的层间扭曲角$ \约1.08^{\ circ} $容纳平坦的频段和展览相关状态,包括莫特般的绝缘子,超导性和磁性。在这里,我们报告了纵向和大厅电阻率接近魔术角TBG的温度依赖性转运测量。虽然观察到的纵向电阻率遵循线性温度$ t $依赖性与以前的报道一致,但霍尔电阻显示出异常的$ t $依赖性,霍尔角cot cot $θ{_h} {_h} \ propto t^2 $。 Boltzmann用于准颗粒传输的理论预测,电阻率和COT $θ{_H} $都应具有相同的$ t依赖性,这与观察到的行为相矛盾。基于准粒子的理论的这种失败让人联想到其他相关的奇怪金属,例如丘比特。
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 $Θ{_H} \propto T^2$. Boltzmann theory for quasiparticle transport predicts that both the resistivity and cot $Θ{_H}$ 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.