E-Book, Englisch, 133 Seiten, eBook
Reihe: Springer Theses
ISBN: 978-3-319-39543-2
Verlag: Springer International Publishing
Format: PDF
Kopierschutz: 1 - PDF Watermark
By performing thermal conductivity and electrical resistivity measurements at temperatures as low as 25mK, the author demonstrates that the Wiedemann–Franz law, a cornerstone of metal physics, is violated at precisely the magnetic-field-induced quantum critical point of the heavy-fermion metal YbRh2Si2. This first-ever observation of a violation has dramatic consequences, as it implies a breakdown of the quasiparticle picture.
Utilizing an innovative technique to measure low-temperature thermal transport isothermally as a function of the magnetic field, the thesis interprets specific, partly newly discovered, high-field transitions in CeRu2Si2 and YbRh2Si2 as Lifshitz transitions related to a change in the Fermi surface. Lastly, by applying this new technique to thermal conductivity measurements of the skutterudite superconductor LaPt4Ge12, the thesis proves that the system is a conventional superconductor with a single energy gap. Thus, it refutes the widespread speculations about unconventional Cooper pairing in this material.
Zielgruppe
Research
Autoren/Hrsg.
Weitere Infos & Material
Introduction.- Theoretical Models.- Experimental Techniques for Transport Measurements.- The Wiedemann-Franz Law in YbRh2Si2.- Kondo Lattices in Magnetic Field.- The Superconducting Order Parameter of LaPt4Ge12.- Summary and Outlook.