科研之友
微信
新浪微博
Facebook
分享链接
摘要
Based on the density functional theory (DFT), a theoretical determination method is applied to find structural and electronic properties of potassium-doped picene. In a unit cell of K(2)picene observed experimentally, the atomic positions and the electronic state are determined within a generalized-gradient approximation of DFT using the plane-wave expansion method. Some metastable structures of K2picene are found in the optimization simulations. Notable properties of a structure with AB stacking, which is the lowest in the energy than others, are 1) appearance of electron doped molecular bands with the band width of 0.1 similar to 0.4 eV, 2) gap formation with a gap of 0.04 similar to 0.1 eV at the Fermi energy, and 3) narrow conduction bands with the band width of similar to 0.1 eV. In all meta-stable structures determined in this study, these characteristics are commonly found. Assuming further electron doping in the conduction bands of K2picene, electron-correlation effects may appear as the pair-hopping processes between doped narrow bands and empty (or filled) broader high-energy bands to stabilize superconductivity by a kind of the Suhl-Kondo mechanism.
- 出版日期2012-12
