论文标题
最小扭曲的双层石墨烯中光电流图案的双曲线增强
Hyperbolic enhancement of photocurrent patterns in minimally twisted bilayer graphene
论文作者
论文摘要
已经深入研究了准周期性的moiré模式及其对扭曲双层石墨烯（TBG）电子特性的影响。由于原子重建，在小扭曲角度$θ$下，Moiré超级晶格将变体变为一个狭窄的域壁网络，将微米级AB和BA堆叠区域分开。我们使用扫描探针光电流成像来解决在这些域壁上发生的Seebeck系数的纳米级变化。观察到的特征在一系列中红外频率范围内增强了，我们用作TBG底物的六边形氮化硼（HBN）是光学上的双曲线。我们的结果说明了纳米 - 光电技术在二维材料中探测纳米级电子不均匀性的新功能。
Quasi-periodic moiré patterns and their effect on electronic properties of twisted bilayer graphene (TBG) have been intensely studied. At small twist angle $θ$, due to atomic reconstruction, the moiré superlattice morphs into a network of narrow domain walls separating micron-scale AB and BA stacking regions. We use scanning probe photocurrent imaging to resolve nanoscale variations of the Seebeck coefficient occurring at these domain walls. The observed features become enhanced in a range of mid-infrared frequencies where the hexagonal boron nitride (hBN), which we use as a TBG substrate, is optically hyperbolic. Our results illustrate new capabilities of nano-photocurrent technique for probing nanoscale electronic inhomogeneities in two-dimensional materials.
