HMC Physics Colloquium
Tuesdays at 16:30 in Shanahan Center for Teaching and Learning, Room B460
California State University, Long Beach
Nov. 27, 2018
C60, the organic molecule made of sixty carbon atoms arranged in soccer-ball looking structure, has brought a lot of excitement to condensed matter physicists, chemists and material scientists since it appearance in 1985. The combination of the buckyball structure made of 20 hexagons and 12 pentagons (a volume known since the time of Leonardo DaVinci) together with important electron-electron and electron-phonon interactions, bring unique properties not seen in ordinary non-molecular crystalline materials. In its bulk form, C60 arranges itself in a face-centered cubic (fcc) lattice (one C60 molecule centered at each lattice site), while in its thin film form it is deposited in a triangular lattice. As an initial approximation one would think that C60’s electronic structure is dominated by the electronic interactions within a single molecule. Instead, we have found that long range interactions between the molecules have a profound effect shaping the electronic structure of the material. In this talk, I will discuss angle resolved photoemission spectroscopy (ARPES) experiments and density functional calculations that support this claim. I will also show an electronic device made of a van der Waals heterostructure composed of a thin film crystalline C60, graphene and hexagonal boron nitride.