Unconventional quantum states of matter in Fe-based superconductors

• Applicant: Professor Dr. Werner Hanke
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2010 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 168111801

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).

• DFG Programme: Priority Programmes
• Subproject of: SPP 1458: High Temperature Superconductivity in Iron Pnictides
• International Connection: Switzerland
• Participating Person: Professor Dr. Ronny Thomale