论文标题
低温下的奇怪的魔法扭曲双层石墨烯的奇怪金属相：从平板到弱耦合的sachdev-ye-kitaev捆绑包
Strange metal phase of disordered magic-angle twisted bilayer graphene at low temperatures: from flatbands to weakly coupled Sachdev-Ye-Kitaev bundles
论文作者
论文摘要
我们使用随机扩张和精确的对角线化来研究无序底物上的魔角扭曲双层石墨烯（TBG）。我们表明，底物诱导的TBG中的强库仑疾病，其水平的化学潜力将系统驱动到弱耦合的Sachdev-Ye-Kitaev（Syk）捆绑包的网络，稳定了出现的TBG的新兴量子chaotic Chaotic Chaotic Chaotic Chaitotic Chaotic奇怪的金属（SM）相位，表现出了缺乏毒素的TBG。高斯正交合奏主导了TBG在强障碍上的长期混沌动力学，而快速量子争夺在短时动力学中出现。在弱点中，TBG的间隙阶段表现出指数衰减的特定热容量和超时订购的相关器（OTOC）的指数衰减。这是相关绝缘体和超导阶段中的系统行为，与相关的相应的Larkin-Ovchinnikov一致。结果表明，在增加疾病强度后，从超导和绝缘相中的隔热相的低温过渡。我们提出了用于库仑二级tbg的有限温度相图，并讨论了新兴SM相的实验后果。
We use stochastic expansion and exact diagonalization to study the magic-angle twisted bilayer graphene (TBG) on a disordered substrate. We show that the substrate-induced strong Coulomb disorder in TBG with the chemical potential at the level of the flatbands drives the system to a network of weakly coupled Sachdev-Ye-Kitaev (SYK) bundles, stabilizing an emergent quantum chaotic strange metal (SM) phase of TBG that exhibits the absence of quasiparticles. The Gaussian orthogonal ensemble dominates TBG's long-time chaotic dynamics at strong disorder, whereas fast quantum scrambling appears in the short-time dynamics. In weak disorder, gapped phases of TBG exhibit exponentially decaying specific heat capacity and exponential decay in out-of-time-ordered correlators (OTOC). This is the system behavior in correlated insulator and superconducting phases, in agreement with the corresponding Larkin-Ovchinnikov result for correlators. The result suggests a low-temperature transition from the superconducting and correlated insulating phases into the strange metal upon increasing the disorder strength. We propose a finite-temperature phase diagram for Coulomb-disordered TBG and discuss the experimental consequences of the emergent SM phase.
