Thermal Transport In Strongly Correlated Rare-earth Intermetallic Compounds (springer Theses)
by Heike Pfau /
2016 / English / PDF
4.2 MB Download
This thesis explores thermal transport in selected
rare-earth-based intermetallic compounds to answer questions of
great current interest. It also sheds light on the interplay of
Kondo physics and Fermi surface changes.
This thesis explores thermal transport in selected
rare-earth-based intermetallic compounds to answer questions of
great current interest. It also sheds light on the interplay of
Kondo physics and Fermi surface changes.
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.
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.
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.
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.
