Tunable Short Periodic Superlattices in Graphene

该项目的目的是在实验演示预测超晶格效应的石墨烯调制的一维周期性电位。虽然二维超晶格已经由许多小组进行了实验研究，例如，根据Hofstadter物理学，一维超晶格也应该导致石墨烯能带结构的强烈修改，这在实验中尚未显示。使用嵌入氮化硼中的高迁移率石墨烯和由薄的几层石墨烯制成的图案化栅极，我们将向传输层施加短周期的可调谐调制电势，并通过磁聚焦实验研究所产生的各向异性能带结构，以及Shubnikov-de哈斯振荡的热阻尼。此外，我们将寻找布洛赫振荡，umklapp电子-电子散射和额外的朗道水平预测存在于石墨烯具有较强的一维调制。

This project aims at an experimental demonstration of predicted superlattice effects in graphene modulated by a one-dimensional periodic potential. While two-dimensional superlattices have been studied experimentally by a number of groups, demonstrating, e.g., Hofstadter physics, one-dimensional superlattices should also lead to a strong modification of the graphene band structure, which has not yet been shown in experiment. Using high-mobility graphene embedded in boron nitride and patterned gates fabricated out of thin few-layer graphene, we will apply a short-period, tunable modulation potential to the transport layer, and study the resulting anisotropic band structure by magnetic focusing experiments, and the thermal damping of Shubnikov-de Haas oscillations. In addition, we will search for Bloch oscillations, umklapp electron-electron scattering and additional Landau levels predicted to exist in graphene with a strong 1D modulation.