Abstract:

In this talk, I report our recent study on the magnetic and pair binding properties in newly discovered polycyclic aromatic hydrocarbon (PAH) superconductors including alkali-metal-doped picene, coronene, phenanthrene, and dibenzopentacene. We have performed a systematic numerical investigation on the possible structure of PAH as functions of pressure and doing. Correlation effects were studied in details. To gain a better understanding on magnetism and electron correlation in PAH, we model the ¦Ð-electrons on the carbon atoms of a single molecule by a one-orbital Hubbard model, in which the energy difference ? between carbon atoms with and without hydrogen bonds is taking into account. We demonstrate that the spin polarized ground state is realized for charged molecules in the physical parameter regions, which provides a reasonable explanation of local spins observed in PAHs. In alkali-metal-doped dibenzopentacene, our results show that electron correlation may produce an effective attraction between electrons for the charged molecule with one or three added electrons. We also propose a different doping pattern which may lead to higher transition temperature.
 
 
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