YBa_2Cu_3O_7能隙及低温物性的第一原理计算

采用密度泛函理论（DFT）中的BLYP和ROBLYP交换．相关泛函，基于YBa2Cu3O7单晶胞即39个原子组成的团簇模型，计算了其能隙、磁化系数、电子比热及比热系数随温度的变化关系，并分析了在不同温度下其最高占据态的分子轨道图。结果表明，YBa2Cu3O7存在3个特征温度Tc、T^＊和T^0，在正常态存在赝能隙，并且其超导能隙和赝能隙均具有d波对称性。

First-Principles Calculation of Energy-Gap and Low-Temperature Physical Character in YBa_2Cu_3O_7

The energy gap, susceptibility, electronic specific heat and its coefficient in YBa2Cu3O7 have been calculated with BLYP and ROBLYP exchange-correlation function in density functional theory on a cluster model of unit cell of 39 atoms. The 3 dimension figures of HOMO at different temperature have been calculated with Gauss-View. The results show that there are 3 characteristic temperature: Tc, T*and T0 in YBa2Cu3O7. Pseudogap has been found in the normal state. Superconducting energy gap and pseudogap are d...