Van Hove singularity and Lifshitz transition in thickness-controlled Li-intercalated graphene
Van Hove singularity and Lifshitz transition in thickness-controlled Li-intercalated graphene
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厚度控制的嵌锂石墨烯中的范霍夫奇点和利夫希茨转变
DOI：
10.1103/physrevb.105.235307
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发表时间：
2022
影响因子：
3.7
通讯作者：
and T. Hirahara
中科院分区：
文献类型：
--
作者：
S. Ichinokura;M. Toyoda;M. Hashizume;K. Horii;S. Kusaka;S. Ideta;K. Tanaka;R. Shimizu;T. Hitosugi;S. Saito;and T. Hirahara
我们展示了一种方法来控制周围的货车霍韦奇点（VHS）的锂插层石墨烯在SiC衬底上的费米能级。通过角分辨光电子能谱，当石墨烯的厚度超过四层时，我们在VHS附近观察到明显的Lifshitz跃迁。我们计算了石墨烯和锂层具有不同堆叠顺序的多层体系的能带结构。所谓的阶段2模型再现了Lifshitz转变，其中Li占据石墨烯的每一个其他夹层。此外，我们发现，一个相当大的肖特基势垒之间形成的石墨烯和衬底。这些性质使我们能够通过控制厚度来探索VHS周围的电子相图。
We demonstrate a method to control the Fermi level around the Van Hove singularity (VHS) in Li-intercalated graphene on the SiC substrate. By angle-resolved photoemission spectroscopy, we observed a clear Lifshitz transition in the vicinity of the VHS when the thickness of graphene exceeds four layers. We calculated the band structure of a multilayer system with different stacking sequences of graphene and Li layer. The so-called stage 2 model reproduces the Lifshitz transition, where Li occupies every other interlayer of graphene. In addition, we found that a sizable Schottky barrier is formed between graphene and the substrate. These properties allow us to explore the electronic phase diagram around the VHS by controlling the thickness.