• 커뮤니티
  • 세미나/콜로퀴움
세미나/콜로퀴움

Strongly Correlated Electron Systems: Dynamical Mean Field Theory Stud…

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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 electrons 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] Under the pressure or chemical doping, the temperature scale can be changed which is related to the movement of the quantum critical point.[3,4] 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 [5] and suggest that the CEF effect enhances the localization of the Yb ions under pressure.[6] We will also discuss the temperature evolution of Kondo resonance band observed in topological Kondo insulator such as SmB6 and YbB6.[7]





References


[1] H. C. Choi et al, Phys. Rev. Lett., 108, 016402 (2012).


[2] H. C. Choi et al, Phys. Rev. B, 88, 125111 (2013).


[3] J. H. Shim et al, Science 318, 1615 (2007).


[4] S. Seo et al, Nat. Commun. 6, 6433 (2015).


[5] S. Ernst et al., Nature (London) 474, 362 (2011).


[6] O. Trovarelli et al., Phys. Rev. Lett. 85, 626 (2000).


[7] J. Denlinger et al., arXiv:1312.6637"
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