TY - BOOK ID - 14202976 TI - Charge Dynamics in 122 Iron-Based Superconductors PY - 2014 SN - 331901191X 3319011928 PB - Cham : Springer International Publishing : Imprint: Springer, DB - UniCat KW - High temperature superconducters. KW - Iron-based superconductors. KW - Iron oxypnictide superconductors KW - Iron oxypnictides KW - Iron pnictide superconductors KW - Iron pnictides KW - Oxypnictide superconductors KW - Oxypnictides KW - Physics. KW - Superconductivity. KW - Superconductors. KW - Nanoscale science. KW - Nanoscience. KW - Nanostructures. KW - Spectroscopy. KW - Microscopy. KW - Optical materials. KW - Electronic materials. KW - Nanotechnology. KW - Strongly Correlated Systems, Superconductivity. KW - Spectroscopy and Microscopy. KW - Optical and Electronic Materials. KW - Nanoscale Science and Technology. KW - High temperature superconductors KW - Molecular technology KW - Nanoscale technology KW - High technology KW - Optics KW - Materials KW - Nanoscience KW - Physics KW - Nano science KW - Nanoscale science KW - Nanosciences KW - Science KW - Electronic materials KW - Analysis, Microscopic KW - Light microscopy KW - Micrographic analysis KW - Microscope and microscopy KW - Microscopic analysis KW - Optical microscopy KW - Analysis, Spectrum KW - Spectra KW - Spectrochemical analysis KW - Spectrochemistry KW - Spectroscopy KW - Chemistry, Analytic KW - Interferometry KW - Radiation KW - Wave-motion, Theory of KW - Absorption spectra KW - Light KW - Spectroscope KW - Superconducting materials KW - Superconductive devices KW - Cryoelectronics KW - Electronics KW - Solid state electronics KW - Electric conductivity KW - Critical currents KW - Superfluidity KW - Qualitative KW - Spectrometry KW - Analytical chemistry UR - https://www.unicat.be/uniCat?func=search&query=sysid:14202976 AB - This thesis combines highly accurate optical spectroscopy data on the recently discovered iron-based high-temperature superconductors with an incisive theoretical analysis. Three outstanding results are reported: (1) The superconductivity-induced modification of the far-infrared conductivity of an iron arsenide with minimal chemical disorder is quantitatively described by means of a strong-coupling theory for spin fluctuation mediated Cooper pairing. The formalism developed in this thesis also describes prior spectroscopic data on more disordered compounds. (2) The same materials exhibit a sharp superconductivity-induced anomaly for photon energies around 2.5 eV, two orders of magnitude larger than the superconducting energy gap. The author provides a qualitative interpretation of this unprecedented observation, which is based on the multiband nature of the superconducting state. (3) The thesis also develops a comprehensive description of a superconducting, yet optically transparent iron chalcogenide compound. The author shows that this highly unusual behavior can be explained as a result of the nanoscopic coexistence of insulating and superconducting phases, and he uses a combination of two complementary experimental methods - scanning near-field optical microscopy and low-energy muon spin rotation - to directly image the phase coexistence and quantitatively determine the phase composition. These data have important implications for the interpretation of data from other experimental probes. ER -