Charge Dynamics in 122 Iron-Based Superconductors / / by Aliaksei Charnukha

• Record Nr.: UNINA9910300381903321
• Autore: Charnukha Aliaksei
• Pubbl/distr/stampa: Cham : , : Springer International Publishing : , : Imprint : Springer, , 2014
• ISBN: 3-319-01192-8
• Edizione: [1st ed. 2014.]
• Descrizione fisica: 1 online resource (139 p.)
• Collana: Springer Theses, Recognizing Outstanding Ph.D. Research, , 2190-5053
• Disciplina: 530.41; 537.6; 537.6233
• Soggetti: Superconductivity; Superconductors; Spectroscopy; Microscopy; Optical materials; Electronic materials; Nanoscale science; Nanoscience; Nanostructures; Nanotechnology; Strongly Correlated Systems, Superconductivity; Spectroscopy and Microscopy; Optical and Electronic Materials; Nanoscale Science and Technology
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Note generali: Description based upon print version of record.
• Nota di bibliografia: Includes bibliographical references.
• Nota di contenuto: Introduction -- Iron-based superconductors -- Experimental and theoretical methods -- Results and discussion -- Summary.
• Sommario/riassunto: 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.