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
469 2020-11-20 16:00  Online  Coherent control of field gradient induced quantum dot spin qubits
468 2020-11-20 14:30  Online  Lumpy Cooper pairs in an iron-based superconductor
467 2020-12-11 14:30  online  Antisymmetric interlayer exchange coupling in magnetic multilayers
466 2020-12-11 16:00  online  Atomic and electronic reconstruction at van der Waals interface in twisted 2D materials
465 2020-12-23 10:00  Online  Online workshop for Quantitative Phase Imaging file
464 2021-02-17 09:00  Online  석학 대중 강연 및 강의 시리즈 file
463 2021-03-02 16:00  Online  Sensitive terahertz detection with graphene-based transistors file
462 2022-03-31 16:00  online  (광학분야 특별세미나)Ultrafast time-resolved spectroscopy in topological materials
461 2022-05-19 15:00  online  (광학분야 특별세미나)Development of a multimodal optical system for improved disease diagnosis
460 2016-09-05 16:00  Natual Scien Bldg.(E6)m #1501  Physics Colloquium : 2016 Fall file
459 2016-05-19 15:00  May 19, 2016 (Thur.) 3PM,  The CERN Resonant WISP Search: Development, Results and Lesson-Learned
458 2017-01-09 16:00  Lecture Hall, College of Natural Sciences [#1501,E6-2]  Topological Defects and Phase Transitions" file
457 2016-04-18 15:30  KI빌딩(E4), 강의실 B501 (5F)  First Principles Approaches for Intermolecular Interactions: From Gas-Phase Dimers to Liquid Water and Molecular Crystal Polymorphism file
456 2014-05-28 17:00  KI Building, Matrix Hall  부품소재산업이 미래다
455 2022-08-09 14:00  KI building (E4), Lecture Room Red (B501)  Quantum biology in fluorescent protein: a new model system to study quantum effects in biology file
454 2023-02-20 17:00  KI building (E4), Lecture Room Red (B501)  (Optics Seminar) Neural Holography for Next generation Virtual and Augmented Reality Displays file
453 2022-01-18 14:00  KI bldg. 5th fl. Room B501 & Zoom  Data-driven interrogation of biological dynamics: from subcellular interactions to neuronal networks in vivo file
452 2016-08-04 14:30  KAIST Natural Science Building (E6-5), EDU 3.0 Room(1st fl.)  Relational Logic (with applications to Quantum Mechanics, String Theory, Cosmology, Neutrino Oscillations, Statistical Mechanics)
451 2016-04-04 09:30  KAIST Natural Science Building (E6-2), RM #4314  Radio frequency engineering
450 2015-10-14 18:00  KAIST Munji Campus Supex Hall  인터스텔라 영화 속의 물리 file