visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2015-12-11 15:45 
일시 2015/12/11, 3:45PM 
장소 E6-2, #1323 
연사 Dr. Ji Hun Sim (POSTECH) 

Dynamical mean field theory studies on heavy fermion system

 

Dec. 11 (Fri.), 15:45 PM, E6-2. 1st fl. #1323
Dr. Ji Hun Sim, POSTECH

 

 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] 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

 

Contact: Heung Sun Sim, Physics Dept., (hs_sim@kaist.ac.kr)

 

번호 날짜 장소 제목
345 2018-10-04 16:00  #1323, E6-2  Engineering light absorption in an ultrathin semiconductor metafilm file
344 2018-10-11 16:00  #1323, E6-2  Dirac electrons in a graphene quasicrystal file
343 2018-10-12 14:30  E6-2. 1st fl. #1323  Quantum Advantage in Learning Parity with Noise file
342 2018-10-12 16:00  E6-2. 1st fl. #1323  Direct observation of a two-dimensional hole gas at oxide interfaces file
341 2018-10-15 16:00  #1323, E6-2  Universal properties of macroscopic current-carrying systems file
340 2018-10-16 10:00  #1323, E6-2  Capturing protein cluster dynamics and gene expression output in live cells file
339 2018-10-18 10:00  #1323, E6-2  Understanding membrane protein folding using single-molecule force techniques file
338 2018-10-18 16:00  #1323, E6-2  Applications of nonlinear optics for condensed matter researches file
337 2018-10-19 10:00  #1323, E6-2  Energy conversion processes during magnetic reconnection in a laboratory plasma file
336 2018-10-24 10:30  E6-1, Lecture Room 1501(1F)  Photonic integration of next-generation clocks and Hertz-absolute-accuarcy optical frequenncy synthesizers file
335 2018-10-25 16:00  #1323, E6-2  Abelian and non-Abelian dark photons file
334 2018-10-26 16:00  #1323, E6-2  Coexisting triple-point and nodal-line topological magnons and thermal Hall effect in pyrochlore iridates file
333 2018-11-01 16:00  #1323, E6-2  Direct holography from a single snapshot file
332 2018-11-08 16:00  #1323, E6-2  Conformality lost file
331 2018-11-09 14:30  E6-2. 1st fl. #1323  Moiré superlattices – from twisted bilayer graphene to quasicrystal file
330 2018-11-09 16:00  E6-2. 1st fl. #1323  Quantum sensing and imaging with diamond defect centers for nano-scale spin physics file
329 2018-11-21 15:00  #1323, E6-2  Engineering topological quantum physics at the atomic scale file
328 2018-11-22 15:00  E6 Room(#1323)  Experimental and Computational Study on Physical Properties based on Granular System file
327 2018-11-23 15:00  E6-2. 2st fl. #2501  Entanglement string and Spin Liquid with Holographic duality file
326 2018-11-29 16:00  #1323, E6-2  양자 칸델라 실현을 위한 단일 광자 발생장치 개발 file