College of Science

SEMINAR: Claudia Ojeda-Aristizabal [CSU Long Beach]

SEMINAR: First observation of highly dispersive bands in thin film C60, Claudia Ojeda-Aristizabal [CSU Long Beach]

Oct 31, 2019 11:00 AM to Oct 31, 2019 12:00 PM at

Physics and Astronomy Seminar

October 31, 2019, 11:00 am to 12:00 pm at Building 8, Room 241

  

Dr. Claudia Ojeda-Aristizabal (CSU Long Beach)

 

First observation of highly dispersive bands in thin film C60


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 its 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 arranged 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 as well as density functional calculations that support this claim. Additionally, I will present the effects of incident light polarization and photon energy dependence on the multiple highly-dispersive valence bands of the C60 thin film.

 

 

 

10:50 am Refreshments

 

11:00 am Seminar