|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  and suggest that the CEF effect enhances the localization of the Yb ions under pressure. We will also discuss the temperature evolution of Kondo resonance band observed in topological Kondo insulator such as SmB6 and YbB6.
 H. C. Choi et al, Phys. Rev. Lett., 108, 016402 (2012).
 H. C. Choi et al, Phys. Rev. B, 88, 125111 (2013).
 J. H. Shim et al, Science 318, 1615 (2007).
 S. Seo et al, Nat. Commun. 6, 6433 (2015).
 S. Ernst et al., Nature (London) 474, 362 (2011).
 O. Trovarelli et al., Phys. Rev. Lett. 85, 626 (2000).
 J. Denlinger et al., arXiv:1312.6637
Contact: Heung Sun Sim, Physics Dept., (firstname.lastname@example.org)
|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|
|137||April 13 (Fri.), 10am||#1323 (E6-2, 1st fl.)||Dr. Sungkun Hong||Quantum meets Mechanics: from Quantum Information to Fundamental Research|
|136||Nov. 3 (Fri.), 4:00 PM||#1323 (1st fl., E6-2.)||Dr. SungDae Ji (Max Planck POSTECH/Hshinchu Center (MPK))||Expedition to the Kitaev Quantum Spin Liquid: Hunting for Majorana fermions|
|135||Nov. 29(Tue) 4p.m.||#1323(E6-2. 1st fl.)||Dr. SungBin Lee, KAIST||Symmetry Protected Kondo Metals and Their Phase Transitions|
|134||Oct. 07 (Fri), 1:30 PM||E6-2. #1323(1st fl.)||Dr. Suk Bum Chung, IBS-CCES , Seoul National University||“Symmetry and topology in transition metal dichalcogenide?”|
|133||April 26 (Fri.), 4:00 PM||#1323, E6-2||Dr. Soonwon Choi||Robust Quantum Metrology using Strongly Interacting Spin Ensembles and Quantum Convolutional Neural Network|
|132||November 5 (Tue.), 4:00 PM||#1323, E6-2||Dr. Shik Shin||Study on nanomaterials by the development of ultrahigh resolution laser-photoelectron microscopy (PEEM)|
|131||November 20 (Wed.), 4:00 PM||#5302, E6-2||Dr. Shigeyuki Ishida||Correlation between superconducting transition temperature and critical current density in irradiated iron-based superconductors|
|130||February 13th (Thur.), 16:30 PM||E6-6, #119||Dr. Seyoon Kim(University of Wisconsin-Madison)||Enhanced Light-Matter Interactions in Graphene with Noble Metal Plasmonic Structures|
|129||October 31 (Thu.), 10:00am||#1323 (E6-2, 1st fl.)||Dr. Seung-Sup Lee||Kondo meets Hubbard: Impurity physics for correlated lattices|
|128||Apr. 09 (Mon.), 11:00 AM||E6-2. 1st fl. #1323||Dr. Seung-Sup B. Lee||Doublon-holon origin of the subpeaks at the Hubbard band edges|
|127||October 29 (Tue.), 4:00pm||#1323 (E6-2, 1st fl.)||Dr. Seung-Joo Lee||Particles and Gravity via String Geometry|
|126||Jun. 01 (Fri.), 11:00 AM||E6-2. 1st fl. #1323||Dr. Seung Sae Hong||Topological phases in low-dimensional quantum materials|
|125||Mar. 29 (Fri.), 02:30 PM||E6-2. 1st fl. #1323||Dr. Seung Hyub Baek||Epitaxial Multifunctional Oxide Thin Films for Novel Electronics|
|124||2016/1/26, 2PM||E6-2, #1323||Dr. Sergei V. Kalinin (Center for Nanophase Materials Sciences, Oak Ridge National Laboratory)||Electrochemistry on Nano- and Atomic Levels: Scanning Probe Microscopy Meets Deep Data|
|123||Apr. 19 (Fri.), 04:00 PM||E6-2. 1st fl. #1323||Dr. Seok Kyun Son||Graphene and hBN heterostructures|
|122||June 17 (Mon.), 10:30 AM||#1323, E6-2||Dr. See-Hun Yang||Chiral Spintronics|
|121||2015/07/15, 2PM||E6-2,1323||Dr. Se Young Park(Rutgers Univ.)||Electronic and optical properties of titanate-based oxide superlattices|
|120||Sep. 29th(Thu), 4PM||E6-2 #1323 (1st floor)||Dr. Sangyoon Han, Department of Physics, KAIST||Large-scale Silicon Photonic MEMS Switches|
|119||Mar. 24 (Fri.), 4:00 PM||#1323 (1st fl. E6-2)||Dr. SangWook Lee||Graphene based nano electronics and nano electromechanics; focusing on precise control of nano structures for studying accurate physical properties|
|118||2015/12/03, 4PM||E6-2, #1323||Dr. Sang-Yun Lee (3rd institute of Physics, University of Stuttgart, Germany)||Hybrid solid state spin qubits in wide bandgap semiconductors|