Evolution of heavy fermion under temperature and pressure changes in heavy fermion compounds and topological Kondo insulator
Ji Hoon Shim,
Department of Chemistry & Physics, Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
In f electron-based heavy fermion compounds, the temperature dependent
behavior of the f electron is determined by the competition between
Kondo effect and RKKY interaction. The f electron's magnetic moments
bind to the itinerant quasiparticles to form composite heavy
quasiparticle bands at low temperature to produce a large Fermi
surface. When the f electrons are localized free moments, a small
Fermi surface is induced with the absence of coherent contribution
from f electrons. In the dynamical mean field theory approach of
Ce-based heavy fermion compounds, we addressed that the Fermi surface
sizes and their effective masses show continuous logarithmic scaling
behavior (~ ln(T0/T)) with different characteristic temperatures.[1,2]
Also, the role of crystalline electric field (CEF) to the spectral
function has been investigated in YbRh2Si2 with well-defined CEF
splitting. We describe the CEF multiplet Kondo resonance peaks similar
to recent experimental observation  and suggest that the CEF effect
enhances the localization of the Yb ions under pressure. We will
also discuss the temperature evolution of Kondo resonance band
observed in topological Kondo insulator such as SmB6 and YbB6.
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 H. C. Choi et al, Phys. Rev. B, 88, 125111 (2013).
 S. Ernst et al., Nature (London) 474, 362 (2011).
 O. Trovarelli et al., Phys. Rev. Lett. 85, 626 (2000).
 J. Denlinger et al., arXiv:1312.6637