visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2015-12-11 15:45 
연사  
장소 E6-2, #1323 

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 연사 제목
공지 2025-02-24 16:00    2025년 봄학기 콜로키움 안내
공지 2025-02-27 16:00    2025년 봄 물리학과 특별세미나 (광학/응집물리 분야)
565 2020-10-16 14:30    Nanoscale magnetic resonance detection towards nano MRI file
564 2015-12-02 16:00    Samarium Hexaboride: Is it a Topological insulator?
563 2020-10-16 16:00    Hidden room-temperature ferroelectricity in CaTiO3 revealed by a metastable octahedral rotation pattern file
562 2015-11-19 16:00    Emergent Collective Phenomena and Functions at Reduced Dimensions
561 2016-05-16 16:00    Tuning microwave cavities with biased nonlinear dielectrics for axion searches
560 2018-10-12 14:30    Quantum Advantage in Learning Parity with Noise file
559 2023-04-04 16:00    Chiral Magnetism: A Geometric Perspective
558 2018-06-22 16:00    Tuning functional properties of BiFeO3 films using strain and growth chemistry file
557 2018-06-22 16:00    Tuning functional properties of BiFeO3 films using strain and growth chemistry file
556 2018-09-05 16:00    Shining a light on fractional excitations file
555 2022-03-18 11:00    (응집물리 세미나) Illuminating exotic states of matter: Raman spectroscopy as an experimental tool to characterize quantum spin liquids file
554 2021-03-02 16:00    Sensitive terahertz detection with graphene-based transistors file
553 2020-11-20 16:00    Coherent control of field gradient induced quantum dot spin qubits
552 2016-11-04 15:00    Quantum information experiments using few electron spins in semiconductors
551 2022-01-17 14:00    Five Lectures on Observational Probes of Dark Energy file
550 2018-11-09 16:00    Quantum sensing and imaging with diamond defect centers for nano-scale spin physics file
549 2022-11-18 16:00    Qubits, new experimental tools for physics file
548 2020-11-20 14:30    Lumpy Cooper pairs in an iron-based superconductor
547 2017-07-10 16:00    “Intertwined Orders in a Heavy-fermion metal” file
546 2022-05-25 14:00    Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia file