论文标题
通过Erbium Intercalation获得的远程超级磷酸的扁平频带和Lifschitz过渡
Flat band and Lifschitz transition in long-range ordered supergraphene obtained by Erbium intercalation
论文作者
论文摘要
无分散能带是一种特殊的特性，它越来越关注新型光子，磁性和电子特性的出现。在这里，我们报告了对Lifshitz过渡的石墨烯超结构N掺杂并表现出平坦带的第一个观察结果，该频带通过单层石墨烯和SIC（0001）之间有序的erbium Intercation获得。 STM实验揭示了大型石墨烯区域，其特征在于远程有序的六角形上层建筑，晶格参数为1.40 nm，相对于原始晶格旋转19度。角度分辨的光电子光谱测量表明，该石墨烯结构具有完美的线性分散剂的狄拉克锥，在费米水平下的dirac点为-1.72 eV +/- 0.02，这是通过互隔断获得的最高掺杂水平之一。费米表面的测量表明，已经达到了Lifshitz的过渡，并且在M点周围产生了宽平面。我们提出，对带结构的这种修饰是诱导的自旋轨道耦合的效果。该系统提供了一个游乐场，以研究由Pi频段状态介导的新型磁性和在费米水平上的状态不同密度之间的相互作用。
Dispersionless energy bands are a peculiar property gathering increasing attention for the emergence of novel photonic, magnetic and electronic properties. Here we report the first observation of a graphene superstructure n-doped up to the Lifshitz transition and exhibiting a flat band, obtained by ordered Erbium intercalation between a single layer graphene and SiC(0001). STM experiments reveal large graphene areas characterized by a long-range ordered hexagonal superstructure with a lattice parameter of 1.40 nm, rotated by 19 degrees with respect to the original lattice. Angle Resolved Photoelectron Spectroscopy measurements show that this graphene structure exhibits Dirac cones with perfect linear dispersion, and a Dirac point at -1.72 eV +/- 0.02 under the Fermi level, which is one of the highest doping levels ever obtained solely by intercalation. Fermi surface measurements show that the Lifshitz transition has been reached, and that a wide flat band is generated around the M point. We propose that this modification of the band structure is the effect of an induced spin-orbit coupling. This system provides a playground to study the interaction between a novel magnetic order mediated by pi-band states, and a divergent density of states at the Fermi level.
