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장소 E6-2, #1323 
일시 2015/12/11, 3:45PM 
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 일시 장소 연사 제목
공지 2019/09/18 - 12/5  Seminar Room #1323  Prof. David Schuster and etc.  Fall 2019: Physics Seminar Serises
공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
119 Mar. 2nd (Thu), 4:00 p.m  #1323(E6-2. 1st fl.)  Dr. Jonathan Denlinger, Lawrence Berkeley National Lab  “Progress in the comparison of ARPES to DMFT for d and f strongly correlated electron systems”
118 Feb. 1 (Wed.), 2p.m.  #1323(E6-2. 1st fl.)  Dr. Michihisa Yamamoto, Department of Applied Physics, The University of Tokyo  Quantum electron optics using flying electrons
117 2017.1.9(Mon), 4PM  Lecture Hall, College of Natural Sciences [#1501,E6-2]  Prof. John Michael Kosterlitz, Brown University  Topological Defects and Phase Transitions" file
116 Dec. 12th (Mon)  1:30p.m. #1323(E6-2. 1st fl.)  Dongjoon Song , AIST  “Possible symmetry in the phase diagrams of electron- & hole-doped cuprate high-Tc superconductors”
115 Dec. 9(Fri), 1:30 p.m.  #1323(E6-2. 1st fl.)  Dr. Jae Yoon Cho, POSTECH  Entanglement area law in strongly-correlated systems
114 Dec. 9(Fri), 4p.m.  #1323(E6-2. 1st fl.  Dr. Kun Woo Kim, KIAS  Shift Charge and Spin Photocurrents in Dirac Surface States of Topological Insulator
113 Dec. 8(Thu) 4p.m.  #1323(E6-2. 1st fl.)  Dr. Jinhyoung Lee, Hanyang University  Dynamical Resonance between Two Optical Cavities via Optomechanical Oscillator
112 Nov. 29(Tue) 4p.m.  #1323(E6-2. 1st fl.)  Dr. SungBin Lee, KAIST  Symmetry Protected Kondo Metals and Their Phase Transitions
111 Nov. 24(Thu) 4p.m.  #1323(E6-2. 1st fl.)  Dr. Jai-Min Choi, Chonbuk National Univiersity  Harmonic oscillator physics with single atoms in a state-selective optical potential
110 Nov. 18th (Fri) 10:30 a.m.  #5318(5th fl.)  Dr. 최 순 원, Havard University  Non-equilibrium many-body spin dynamics in diamond
109 Nov. 16 (Wed), 4p.m.  #1323(E6-2. 1st fl.)  Dr. Heung-Sik Kim , University of Toronto  Realizing Haldane Model in Fe-based Honeycomb Ferromagnetic Insulators
108 Nov. 10th(Thu) 4 p.m.  E6-2. #1323(1st fl.)  Prof. Min Seok Jang, Electrical Engineering, KAIST  Low Dimensional Active Plasmonics and Electron Optics in Graphene
107 Nov. 11th (Fri), 4 p.m.  #1323(E6-2. 1st fl.)  Dr. Bohm-Jung Yang, SNU  Dirac fermions in condensed matters
106 Nov. 11th(Fri), 1:30 p.m.  #1323(E6-2. 1st fl.)  Dr. Keun Su Kim, POSTECH  Bandgap Engineering of Black Phosphorus
105 Nov. 04 (Fri), 3:00 PM  E6-2. #1323(1st fl.)  Dr. Dohun Kim, Department of Physics and Astronomy, SNU  Quantum information experiments using few electron spins in semiconductors
104 Nov. 04 (Fri), 1:30 PM  E6-2. #1323(1st fl.)  Dr. Jonghyun Song, Department of Physics, Chungnam National University  Exotic phenomena at oxide LaAlO3/SrTiO3 hetero-interface and their applications
103 Nov. 1st (Tue), 10:30AM  #1323(E6-2 1st fl.)  Dr. Gadi Eisenstein, Technion  Time scale dependent dynamics in InAs/InP quantum dot gain media
102 Oct. 27th(Thu) 4PM  #1323(E6-2)  Dr. 이 강 희, KAIST, Mechnical Engineering  Terahertz Metal Optics
101 Nov. 1 (Tue.) 2:30 pm  Seminar Room #1323(E6-2)  Prof. Youngjoon Kwon, Yonsei Univ.  Search for dark sector particles in the B-factory experiments
100 Oct. 17th (Mon) 11:00 AM  #1323,(E6-2, 1st fl.)  Nguyen Quang Liem, Institute of Materials Science, VAST, Viettnam  IMS and examples of the studies on optoelectronic materials