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장소 #1323 (1st fl., E6-2.) 
일시 Nov. 3 (Fri.), 4:00 PM 
연사 Dr. SungDae Ji (Max Planck POSTECH/Hshinchu Center (MPK)) 

The seminal work of Anderson triggered a great deal of theoretical and experimental efforts to search for the novel quantum spin liquid (QSL) states in matters, and it has become one of central issues in contemporary condensed matter physics. The QSL state, a long-range quantum entangled state, is represented by a topological order and fractionalization of constituent magnetic moments. While the most QSL states have been described by deconfined spinons as an elementary excitation in frustrated magnets, Kitaev’s QSL state is exactly derived by fractionalizing the spin excitation into Majorana fermions in a two-dimensional honeycomb lattice, the so-called Kitaev lattice, with the ansatz of bond dependent Ising-like spin interaction. In the past decade, experimental realization of the fascinating Kitaev honeycomb QSL model has been eagerly pursued. In this talk, I will present the experimental evidences of fractionalized Majorana fermions in a high quality α-RuCl3 single crystal. Neutron and x-ray diffraction measurements reveal that the low-temperature crystal structure forms the perfect Ru-honeycomb lattice, which provides an ideal platform for the Kitaev honeycomb quantum spin lattice. Extensive thermodynamic and neutron spectroscopic measurements directly proved fractionalized Majorana fermion excitations as a result of thermal fractionalization of Jeff = ½ pseudospins, which is well reproduces by numerical predictions obtained from the Kitaev model.

 

20171103_지성대.pdf

번호 일시 장소 연사 제목
공지 2017/09/14 - 12/07  Seminar Room #1323  Prof. 정광용 교수(Gacheon Univ) and etc.  Fall 2017: Physics Seminar Serises
공지 2017/09/04 - 12/04  Seminar Room 1501  Prof. Sangsu Bae(Hanyang Univ.) and etc.  Fall 2017: Physics Colloquium
145 Nov. 8 (Wed.), 1:00 PM  #5318 (E6-2. 5th fl.)  Prof. Y. Matsuda Department of Physics, Kyoto University  “Emergent exotic quasiparticles in quantum spin liquids” file
» 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 file
143 Nov. 3 (Fri.), 2:30 PM  #1323 (1st fl., E6-2.)  Dr. MinChul Lee(Department of Applied Physics, Kyung Hee Univ.)  Quantum Resistor-Capacitor Circuit with Majorana Edge States file
142 Oct. 10(Tue) 4PM  E6-2 #1323  김성웅 교수 (성균관대학교 에너지과학과)  Discovery of New 2D Materials with Diverse Physical Properties
141 Sep. 22 (Fri.), 04:00 PM  E6-2. 1st fl. #1323  Dr. GilHo Lee / Department of Physics, POSTECH  Unexpected Electron-Pairing in Integer Quantum Hall Effect file
140 Sep. 22 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. GilHo Lee / Department of Physics, POSTECH  Quantum Electronic Transport in Graphene Hybrid Nanostructures file
139 Sep. 22 (Fri.), 01:00 PM  E6-2. 1st fl. #1323  Dr. EunSeong Kim / Department of Physics, KAIST  Superconductor-metal-insulator transition in thin Tantalum films file
138 Sep. 26 (Tue.), 11AM  #1323 (E6-2. 1st fl.)  Dr. Yukiaki Ishida / ISSP, University of Tokyo  Time-resolved ARPES study of Dirac and topological materials
137 Sep. 13 (Wed.), 4 PM  #1323 (E6-2. 1st fl.)  Prof. Yi. Zhou (The Zhejiang Univ.)  An Introduction to Quantum Spin Liquids file
136 Sep. 12 (Tue.), 4 PM  #1323 (E6-2. 1st fl.)  Prof. Yi. Zhou (The Zhejiang Univ.)  Exact Solution for the Interacting Kitaev Chain at Symmetric Point file
135 AUG. 31 (Thu.), 2 PM  #5318(E6-2. 5th fl.)  Prof. Hiroaki Ishizuka (The University of Tokyo)  “Berry phase and nonlinear response: photocurrent in noncentrosymmetric insulators and Weyl semimetals” file
134 Aug. 16 (Wed.), 4 PM  #1322 (E6-2. 1st fl.)  Prof. Noejung Park (UNIST)  Phonon-driven spin-Floquet valleytro-magnetism file
133 July. 14 (Fri.), 3:00 PM  #1323 (E6-2. 1st fl.)  Dr. Jun Hyun Lee / University of Maryland  Chiral anomaly in disordered Weyl semimetals file
132 #1323(E6-2. 1st fl.)  Jul. 10th (Mon), 4pm  Dr. Duk Young Kim Los Alamos National Laboratory  “Intertwined Orders in a Heavy-fermion metal” file
131 Jun. 2 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. Euyheon Hwang(황의헌)  Quasiparticle Interference and Fourier transform scanning tunneling spectroscopy in WTe2 (Weyl semimetal) file
130 Jun. 2 (Fri.), 4:00 PM  #1323 (E6-2. 1st fl.)  Dr. Sang Wook Kim  Maxwell's demon in quantum wonderland file
129 May. 12 (Fri.), 01:30 PM  E6-2. 1st fl. #1323  Dr. Young Kuk Kim  Topological Dirac insulator
128 Apr. 27, 2017 (Thu) 4:00 pm  Seminar Room(#1323, E6-2)  Prof.Donghan Lee (Chungnam National Univ.)  반도체 양자점을 이용한 단광자 광원