芳烃超导体的晶体结构和电子态的理论研究

项目名称： 芳烃超导体的晶体结构和电子态的理论研究

项目编号： No.11474004

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 闫循旺

作者单位： 安阳师范学院

项目金额： 86万元

中文摘要： 2010年，菲和苉晶体（钾掺杂）中超导电性的发现，开辟了芳烃超导研究的新领域。作为新材料，其晶体结构是一切性质的研究基础。当前，从多个结构相中确定真实的超导相，准确把握其电子结构，是实验和理论上的研究瓶颈。本课题以苉、六苯并苯等芳烃晶体为代表材料，借助结构搜索（CALYPSO软件）、过渡态寻找（NEB方法）、X-ray衍射谱模拟和Raman谱模拟，结合实验数据，甄别并确定出真实超导相的晶体结构；运用多种关联近似下的电子态模拟和理论分析，归纳出芳烃超导体电子结构的关键特征；通过取代、剪裁原子基团，替换掺杂金属等方法，设计和预测新的芳烃超导体；模拟掺杂后体系的声子谱，判断所预测结构的动力学稳定性，计算电声耦合强度，依据MacMillan公式估算其对超导的贡献。该研究有利于全面准确地理解该类材料中电荷、自旋和晶格等自由度间的相互作用，为揭示其超导配对机制提供重要的科学依据。

中文关键词： 电子结构；第一性原理计算；有机超导体；超导电性；芳烃

英文摘要： In 2010, the discovery of superconductivity in K-intercalated picene and phenanthrene opened up a new research field of aromatic supercondcutor. For a new material, the crystal structure is the base to investigate its physical and chemical properties. So, the determination of superconducting phase from various crystal phases coexisted in sample and displaying the accurate electronic structure are the difficult problems in theoretical and experimental study at present. By the means of structure prediction, transition state search, X-ray diffraction peak fitting and Raman spectra simulation methods, we take K-doped picene and cronene as the typical compounds to find out and investigate the atomic structure of superconducting phase. We also adopt several exchange-correlation potentails to simulate the electronic states, and extract and induce the key feature of electronic structure for metal-doped aromatic hydrocaborn superconductors. Then we will design and predict some new aromatic superconductors by substitution of atomic group, tailoring or replacing different metal atoms. The dynamic characters of these compounds will be studied, including phonon frequency, electron-phonon coupling strength, estimation of superconducting transition temperature. Our research project is important for the understanding to the electron, spin, orbital and lattice interaction, and can provide a scientific basis for the exploration of the pairing mechanism in the metal-intercalated aromatic superconductor.

英文关键词： electronic structure;first principle calculation;organic superconductor;superconductivity;aromatics