Twisted bilayer graphene has a rich phase diagram, including superconductivity. Recently, an unexpected discovery been the observation of superconductivity in non-twisted bilayers and trilayers. In this Perspective, we give overview search for uncommon phases systems. We first contextualize these recent results within earlier work field, before examining new experimental findings. Finally, anal...

Graphene is of interest in the development next-generation electronics due to its high electron mobility, flexibility and stability. However, graphene transistors have poor on/off current ratios because absence a bandgap. One approach introduce an energy gap use hydrogenation reaction, which changes into insulating graphane with sp3 bonding. Here we show that electric field can be used control ...

Abstract Motivated by measurements of compressibility and STM spectra in twisted bilayer graphene, we analyze the pattern symmetry breaking for itinerant fermions near a van Hove singularity. Making use an approximate SU(4) Landau functional, show that structure spin/isospin order parameter changes with increasing filling via cascade transitions. We compute feedback from different orders on arg...

While thermally cycling monolayer, bilayer, and trilayer graphene between 5 K 300 K, Raman spectroscopy has shown that cooling to induces a strain in these flakes of ?0.081 ± 0.003%. This was used measure the thermal expansion coefficient (TEC), which found be (?3.2 0.2)×10?6 K?1 for monolayers, (?3.4 0.4)×10?6 bilayers, (?3.8 0.6)×10?6 trilayers at room temperature. The TEC showed similar temp...

Stimulated by the recent experimental synthesis of a new layered carbon allotrope-graphdiyne film, we provide the first systematic ab initio investigation of the structural and electronic properties of bilayer and trilayer graphdiyne and explore the possibility of tuning the energy gap via a homogeneous perpendicular electric field. Our results show that the most stable bilayer and trilayer gra...