Introducing strong correlation effects into graphene by gadolinium intercalation

Unexpected Structures for Intercalation of Sodium in Epitaxial Graphene-SiC Interfaces

We show using scanning tunneling microscopy, spectroscopy, and ab initio calculations that several intercalation structures exist for Na in epitaxial graphene on SiC(0001). Intercalation takes place at room temperature and Na electron-dopes the graphene. It intercalates in-between single-layer graphene and the carbon-rich interfacial layer. It also penetrates beneath the interfacial layer and decouples it to form a second graphene layer. This decoupling is accelerated by annealing and is verified by direct Na deposition onto the interface layer. Our observations show that intercalation in grap…

Eu插层Kekulé有序石墨烯中折叠Dirac带的巨劈裂

Giant Splitting of Folded Dirac Bands in Kekulé-ordered Graphene with Eu Intercalation

本文通过在石墨烯/SiC界面插层Eu形成Kekulé有序结构，结合ARPES与DFT发现Kekulé序折叠Dirac锥并与Eu 4f局域磁矩强耦合，导致折叠Dirac带巨劈裂，为石墨烯自旋电子学应用开辟新途径。

First Principle Study of Alkaline Metal Intercalation in Twisted Bilayer Graphene

The intercalant alkaline metals, Ca, Sr, & Ba, are sources of a periodic perturbation on the bilayer graphene, which leads to the formation of an N-type semiconductors. The twist angle between graphene layers applies disorder to the intercalated bilayer graphene to tune the bandgap. The twisted bilayer graphene structures of C8MC8 (M: Ca, Sr, Ba) were studied for the Energy band diagrams, Density of States, transport properties of Seebeck coefficient, Hall coefficient, Thermal conductivity, and Electrical conductivity using Quantum-Espresso and BoltzTrap software. The bandgap enhances with res…

Tuning Conductivity and Spin Dynamics in Few-Layer Graphene via In Situ Potassium Exposure

Chemical modification, such as intercalation or doping of novel materials is of great importance for exploratory material science and applications in various fields of physics and chemistry. In the present work, we report the systematic intercalation of chemically exfoliated few-layer graphene with potassium while monitoring the sample resistance using microwave conductivity. We find that the conductivity of the samples increases by about an order of magnitude upon potassium exposure. The increased of number of charge carriers deduced from the ESR intensity also reflects this increment. The do…

Tunable hybridization of electronic states of graphene and a metal surface

We present an approach to monitor and control the strength of the hybridization between electronic states of graphene and metal surfaces. Inspecting the distribution of the $π$ band in a high-quality graphene layer synthesized on Ni(111) by angle-resolved photoemission, we observe a new "kink" feature which indicates a strong hybridization between $π$ and \textit{d} states of graphene and nickel, respectively. Upon deposition and gradual intercalation of potassium atoms into the graphene/Ni(111) interface, the "kink" feature becomes less pronounced pointing at potassium mediated attenuation of…