论文标题
紧张的扭曲双层石墨烯中相互作用增强的拓扑厅效应
Interaction-Enhanced Topological Hall Effects in Strained Twisted Bilayer Graphene
论文作者
论文摘要
我们分析了远程库仑相互作用对差距与六角硼硝化硼(HBN)紧密对齐的扭曲双层石墨烯(TBG)的晶体中性相近浆果曲率分布的影响。由于狭窄带的抑制分散体,通过电子 - 电子相互作用将带结构重新归一化,因此,带的相关拓扑特性对填充很敏感。我们使用Hartree形式主义,计算线性和非线性大厅的电导率,并发现在某些填充物中,远程带对霍尔电流有很大的贡献,而中央频段的贡献被抑制。特别是,我们发现这些电流在能量的区域附近是一般实质性的,在该区域中,频带彼此高度纠缠,通常以掺杂诱导的带反转为特征。我们的结果表明,TBG/HBN中的拓扑转运通过电子电子相互作用而实质上改变了,这为最近的实验结果提供了简单的解释。
We analyze the effects of the long-range Coulomb interaction on the distribution of Berry curvature among the bands near charge neutrality of twisted bilayer graphene (TBG) closely aligned with hexagonal boron nitride (hBN). Due to the suppressed dispersion of the narrow bands, the band structure is strongly renormalized by electron-electron interactions, and thus, the associated topological properties of the bands are sensitive to filling. Using a Hartree formalism, we calculate the linear and nonlinear Hall conductivities, and find that for certain fillings, the remote bands contribute substantially to the Hall currents while the contribution from the central bands is suppressed. In particular, we find that these currents are generically substantial near regions of energies where the bands are highly entangled with each other, often featuring doping-induced band inversions. Our results demonstrate that topological transport in TBG/hBN is substantially modified by electron-electron interactions, which offer a simple explanation to recent experimental results.