We examine the quantum Hall effect in bilayer graphene grown on Cu substratesby chemical vapor deposition. Spatially resolved Raman spectroscopy suggests amixture of Bernal (A-B) stacked and rotationally faulted (twisted) domains.Magnetotransport measurements performed on bilayer domains with a wide 2D bandreveal quantum Hall states (QHSs) at filling factors $\nu=4, 8, 12$ consistentwith a Bernal stacked bilayer, while magnetotransport measurements in bilayerdomains defined by a narrow 2D band show a superposition of QHSs of twoindependent monolayers. The analysis of the Shubnikov-de Haas oscillationsmeasured in twisted graphene bilayers provides the carrier density in eachlayer as a function of the gate bias and the inter-layer capacitance.
展开▼
机译：我们研究了通过化学气相沉积在铜基板上生长的双层石墨烯中的量子霍尔效应。空间分辨拉曼光谱表明存在伯纳尔（AB）堆叠和旋转断层（扭曲）畴的混合物，在填充因子$ \ nu = 4、8、12与Bernal叠层双层相一致，而在由窄2D谱带定义的双层畴中的磁传输测量结果显示了两个独立单层的QHS叠加。在扭曲的石墨烯双层中测量的Shubnikov-de Haas振荡的分析提供了每一层的载流子密度，该密度是栅极偏置和层间电容的函数。
展开▼
