visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
장소 E6-2, #1323 
일시 2015/12/11, 1:30PM 
연사 Dr. KwangYong Choi  (Chung-Ang University) 

Quantum spin liquid in the 1/3 depleted triangular lattice Ba3(Ru1-xIrx)Ti2O9

 

Dec. 11. (Fri.), 13:30 PM,  E6-2. 1st fl. #1323
Dr. KwangYong Choi  (Chung-Ang University)

 

Geometrically frustrated antiferromagnets are a versatile reservoir for emergent quantum-correlated phenomena such as spin liquids, fractionalized excitations, and magnetic monopoles. Recent experiments on the 6H-perovskite family Ba3AB2O9 (A=Cu, Ni, Co, Ru, Ir; B=Sb, Ti) have disclosed a variety of interesting ground states: a random singlet, spin liquid, spin freezing, and 120? ordering, depending on a spin number, spin-orbit coupling, and Jahn-Teller (JT) distortions. In this talk, I will briefly introduce spin liquid in the context of topological order and then present experimental results on the two materials Ba3CuSb2O9 and Ba3Ru1-xIrxTi2O9. In Ba3CuSb2O9, a combined effect of frustration and local JT distortions may create a novel spin-orbital entangled state. Our ESR results provide evidence for intrinsic coupling of spins to orbital degrees of freedom and thereby demonstrate that magnetism is dictated by a spatiotemporal structure of the JT distortions. In Ba3Ru1-xIrxTi2O9, a 1/3 depleted triangular lattice with strong spin-orbit coupling we address the possibility of spin-orbit tuned spin liquids. For the 4d Ru compound, we find experimental signatures of a coexisting spin freezing and dynamically fluctuating state. In the 5d Ir counterpart, spin-orbit coupling melts residual spin freezing while stabilizing a spin liquid state. Our comparative study evidences that spin depletion and spin-orbit coupling conspire to promote a quantum spin liquid in triangular antiferromagnets.

 

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
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
127 Apr. 28 (Fri.), 04:00 PM  #1323 (E6-2. 1st fl.)  Dr. Minkyung Jung Research Institute, DGIST  Carbon nanotubes coupled to superconducting impedance matching circuits
126 Apr. 28 (Fri.), 02:30 PM  E6-2. 1st fl. #1323  Dr. JeongYoung Park Graduate School of EEWS, KAIST  Hot electron generation at surfaces and its impact to catalysis and renewable energy conversion
125 April 6, 2017 (Thu), 4:00 pm  IBS CAPP seminar room, Creation Hall (3F), KAIST Munji Campus  Prof. Youngjoon Kwon (Yonsei University)  For whom the Belle tolls
124 April 5th 2017, 12:00 ~ 13:00  Room 101, Creative Learning Bldg.(E11)  Prof. Wonho Choe(Dept. of Physics),Prof. Young-chul GHIM(Dept. of Nuclear & Quantum Engineering)  2017년 4월 첫수 융합포럼 개최 안내(물리학과 & 원자력 및 양자공학과 공동 개최)/The First Wednesday Multidisciplinary Forum in April 2017 organized by Dept. of Physics & Dept. of Nuclear & Quantum Engineering file
123 2017/03/06 - 05/29  Seminar Room 1501  이종봉 박사 (POSTECH) 외  Spring 2017: Physics Colloquium file
122 2017/03/21 - 06/08  Seminar Room 1323  조길영 박사(KAIST) 외  Spring 2017: Physics Seminar Serises file
121 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
120 Mar. 24 (Fri.), 2:30 PM  #1323 (1st fl. E6-2).  Dr. MahnSoo Choi  Topological Dynamics