2008/10/09 by M. S. Laad, Laad, M. S., L. Craco +7
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.0810.1607
14 pages, 13 figures
arxiv created 2008/10/09 · openalex publication_date 2008/10/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The recent discovery of high-temperature superconductivity (HTSC) in doped Iron pnictides is the latest example of unanticipated behavior exhibited by d- and f-band materials. The symmetry of the SC gap, along with the mechanism of its emergence from the ``normal'' state is a central issue in this context. Here, motivated by a host of experimental signatures suggesting strong correlations in the Fe-pnictides, we undertake a detailed study of their normal state. Focussing on symmetry-unbroken phases, we use the correlated band structure method, LDA+DMFT, to study the one-particle responses of both \rm LaO1-xFeAsFx and \rm SmO1-xFeAsFx in detail. Basing ourselves on excellent quantitative agreement between LDA+DMFT and key experiments probing the one-particle responses, we extend our study, undertaking the first detailed study of their normal state electrodynamic response. In particular, we propose that near-total normal state incoherence, resulting from strong, \it local correlations in the Fe d-shell in Fe-pnictides, underpins the incoherent normal state transport found in these materials, and discuss the specific electronic mechanisms leading to such behavior. We also discuss the implications of our work for the multi-band nature of the SC by studying the pairing ``glue'' function, which we find to be an overdamped, electronic continuum. Similarities and differences between cuprates and Fe-pnictides are also touched upon. Our study supports the view that SC in Fe-pnictides arises from a bad metallic, incoherent ``normal'' state that is proximate to a Mott insulator.