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장소 1st fl. #1323(E6-2) 
일시 Oct. 18 (Tue.), 1:30 PM 
연사 Dr. Chan-Ho Yang, Department of Physics, KAIST 

"Visualization of oxygen vacancy in motion and the interplay with electronic conduction"

 

Dr. Chan-Ho Yang, Department of Physics, KAIST
Oct. 18 (Tue.), 1:30 PM, 1st fl. #1323(E6-2)


Abstract:

The multiferroic BiFeO3 (BFO) is an interesting playground to explore correlated electronic conduction. Here, we substitute divalent Ca ions into the parent BFO and apply an external electric field at elevated temperatures to spatially redistribute spontaneously created oxygen vacancies, thereby generating hole carriers in regions of less dense oxygen vacancy concentrations. X-ray diffraction and photoemission spectroscopic measurement are employed to quantify a large variation of local oxygen vacancy concentration as much as ~1021 cm-3 and explore the consequent evolution of electronic band structure. We find that a non-rigid polaronic band is created by hole doping as a result of a strong electron-lattice coupling. We also show strong evidence for the disorder-driven formation of a Coulomb glass state through electronic transport measurement on a quantitative level. These spectroscopic and transport results can be combined and understood in the framework of intrinsic spatial inhomogeneity of polaronic charge density. Dynamical properties of oxygen vacancy in motion will be also discussed in a spatial-resolved way. The finding offers a promising platform and methodology for examining the interplay of functional defects and correlated electronic behaviors.

 

Contact: SunYoung Choi, (sunyoungchoi@kaist.ac.kr)
Center for Quantum Coherence in Condensed Matter, KAIST

번호 일시 장소 연사 제목
공지 2018/09/20 - 11/29  Seminar Room #1323  손주혁 교수(서울시립대 물리학과) and etc.  Fall 2018: Physics Seminar Serises
공지 2018/08/27 - 12/03  Seminar Room 1501  김승중 교수 (KAIST) and etc.  Fall 2018: 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