Unconventional quantum states of matter in Fe-based superconductors

该项目的主要目标是对铁磷属元素化物的高温超导性（SC）进行微观描述。与实验小组合作（特别是，进行光电发射、光学和拉曼实验）我们希望进一步澄清在考虑配对机制、配对状态的对称性等时“什么是材料特异性的，什么是普遍的”。特别感兴趣的是在更广泛的材料类别中是否存在SC的普遍电子机制的基本问题，其中铁磷属元素和铜酸盐代表两个特征族，其中强反铁磁相关驱动其它有序化倾向。应用功能重整化群（fRG）技术支持的其他方法（densityfunctional理论，集群技术），我们计划系统地研究晶格结构的影响，电荷波动（p带）和特定的声子（磁振子-声子耦合）SC状态，其临界温度和对称性（时间反演对称性破缺状态的可能性）。

The principal goal of this project is a microscopic description of high-temperature superconductivity (SC) in the iron pnictides. In collaboration with experimental groups (in particular, carrying out photoemission, optical and Raman experiments) we would like to further clarify ”what is material specific and what is universal” when considering the pairing mechanism, the symmetry of the pairing state, etc. Of particular interest is the fundamental question whether there exists a universal electronic mechanism of SC in a wider class of materials, with the iron pnictides and the cuprates representing two characteristic families, where strong antiferromagnetic correlation drives other ordering tendencies. Applying the functional renormalization group (fRG) technique supported by other methodologies (densityfunctional theory, cluster techniques), we plan to systematically study the influence of the lattice structure, of charge fluctuations (p-bands) and of specific phonons (magnon-phonon coupling) on the SC state, its critical temperature and symmetry (possibility of a time-reversal symmetry breaking state).