Superconductivity in graphene on surfaces

石墨烯的独特性质缺乏超导性。在石墨烯中实现超导态的理论建议已经发表，例如碱金属插层或通过邻近效应注入库珀对。然而，预测情景的实验证据很少，甚至没有。因此，拟议研究项目的主要目标是填补实验验证的空白。为此，将用表面科学的方法分析简单的模型系统。在金属表面的石墨烯中，通过两种方法可以诱导超导电性。首先，Li将被吸附在Ir(111)上的单层和双层石墨烯上。其次，邻近效应将被用来将Nb(110)中的库珀对注入到单个吸附的石墨烯薄片中。超导态对非磁性(Ag)和磁性(Fe，Mn)杂质存在的响应将被超导石墨烯能隙内共振的存在或不存在所揭示。低温扫描隧道显微镜和光谱以及角度分辨的非弹性电子散射将被用来获得石墨烯超导的全面图像。

The repertoire of unique graphene properties is lacking superconductivity. Theoretical suggestions for achieving the superconducting state in graphene, e.g., alkali metal intercalation or injection of Cooper pairs by the proximity effect, have been published. Experimental evidence for the predicted scenarios, however, is scarce or even absent. The main target of the proposed research project is thus filling the gap of experimental verification. To this end simple model systems will be analyzed in a surface science approach. Superconductivity shall be induced in graphene on metal surfaces by two procedures. First, Li will be adsorbed on single-layer and bilayer graphene on Ir(111). Second, the proximity effect will be used to inject Cooper pairs from Nb(110) into a single adsorbed graphene sheet. The response of the superconducting state to the presence of nonmagnetic (Ag) and magnetic (Fe, Mn) impurities will be unravelled by the presence or absence of resonances inside the energy gap of superconducting graphene. Low-temperature scanning tunnelling microscopy and spectroscopy together with angle-resolved inelastic electron scattering will be used to obtain a comprehensive picture of graphene superconductivity.