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
427 2021-05-14 16:00  Online seminar  Spatial and temporal separation of environmental dephasing sources from solid-state quantum emitters file
426 2016-04-12 16:00  E6-2. 1st fl. #1323  Confinement of Superconducting Vortices in Magnetic Force Microscopy
425 2017-04-28 14:30  E6-2. 1st fl. #1323  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
» 2015-12-11 15:45  E6-2, #1323  Dynamical mean field theory studies on heavy fermion system
423 2023-10-19 11:00  E6-2 #1322  Emergent functionalities of iridium oxide films with different growth orientation file
422 2023-06-26 11:00  E6, Rm#1323  Quantum computing on magnetic racetracks with flying domain wall qubits
421 2019-04-19 11:00  #1323, E6-2  First-principles studies of semiconductors for solar cell applications file
420 2021-06-11 14:30  Online seminar  Engineering sound waves and vibrations in multi-mode nanomechanical systems file
419 2019-09-27 16:00  E6-2. 1st fl. #1323  0D/1D/2D/3D III-V materials grown by MBE for Optelectronics file
418 2018-03-16 14:30  E6-2. 1st fl. #1323  산화물 다층박막에서의 다양한 물리현상 file
417 2018-03-16 14:30  E6-2. 1st fl. #1323  산화물 다층박막에서의 다양한 물리현상 file
416 2016-12-8 16:00  #1323(E6-2. 1st fl.)  Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator
415 2023-05-22 13:00  E6-6 119  Design & Development of Electrochemical Biosensors for the Detection of T2DM Biomarkers
414 2017-03-02 16:00  #1323(E6-2. 1st fl.)  “Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”
413 2019-12-03 16:00  #1323, E6-2  Toward Quantum Materials with Correlated Oxides file
412 2016-04-01 16:15  E6-2. 1st fl. #1501  Cotunneling drag effect in Coulomb-coupled quantum dots
411 2015-08-03 10:30  E6-2, #1323 (Seminar Room)  Axion Search
410 2016-11-04 13:30  E6-2. #1323(1st fl.)  Exotic phenomena at oxide LaAlO3/SrTiO3 hetero-interface and their applications
409 2018-10-19 10:00  #1323, E6-2  Energy conversion processes during magnetic reconnection in a laboratory plasma file
408 2018-12-07 16:00  E6-2. 1st fl. #1323  Novel probes of interacting electrons in 2D systems file