论文标题
可调的大浆果偶极子在紧张的扭曲双层石墨烯中
Tunable large Berry dipole in strained twisted bilayer graphene
论文作者
论文摘要
最近的实验测量了扭曲双层石墨烯（TBG）中的局部单轴应变场。我们的计算发现，通过打破sublattice对称性而产生的有限浆果曲率和这些TBG中狭窄带之间的频带接近性诱导了10 \，nm或更大的较大级浆果偶极子。大浆果偶极子导致横向拓扑非线性电荷电流，该电流在实验可访问的跨界跨界电流上占主导地位，$ \ sim 0.1 {\ rm mv} /μ\ rm {m rm {m} $。由于应变参数，电子填充物，间隙尺寸和温度，由于浆果偶极子引起的这种异常的大厅效应非常可调。
Recent experiments have measured local uniaxial strain fields in twisted bilayer graphene (TBG). Our calculations found that the finite Berry curvature generated by breaking the sublattice symmetry and the band proximity between narrow bands in these TBG induces a giant Berry dipole of order 10\,nm or larger. The large Berry dipole leads to transverse topological non-linear charge currents which dominates over the linear bulk valley current at experimentally accessible crossover in-plane electric field of $\sim 0.1 {\rm mV} / μ\rm{m}$. This anomalous Hall effect, due to Berry dipole, is strongly tunable by the strain parameters, electron fillings, gap size, and temperature.
