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Nguyen TH, Son J, Kim S, Cho H, Kim CH, Wang YP, Burch KS, Yang IS, Jeong J, Park JG, Moon SJ, Noh TW. Topological Magnon Band Crossing in Y_{2}Ir_{2}O_{7}. Phys Rev Lett 2021; 127:267203. [PMID: 35029465 DOI: 10.1103/physrevlett.127.267203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 11/22/2021] [Indexed: 06/14/2023]
Abstract
Topological magnonic materials have attracted much interest because of the potential for dissipationless spintronic applications. Pyrochlore iridates are theoretically regarded as good candidates for designing topological magnon bands. However, experimental identification of topological magnon bands in pyrochlore iridates remains elusive. We explored this possibility in Y_{2}Ir_{2}O_{7} using Raman spectroscopy to measure both the single-magnon excitations and anomalous phonon shifts. From the single-magnon energies and tight-binding model calculations concerning the phonons, we determined the key parameters in the spin Hamiltonian. These confirm that Y_{2}Ir_{2}O_{7} hosts a nontrivial magnon band topology distinct from other pyrochlore iridate compounds. Our work demonstrates that pyrochlore iridates constitute a system in which the magnon band topology can be tailored and that Raman spectroscopy is a powerful technique to explore magnon band topology.
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Affiliation(s)
- Thi Huyen Nguyen
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Jaeseok Son
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Soyeun Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Hwanbeom Cho
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Choong H Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Y P Wang
- Physics Department, Boston College, Boston, Massachusetts 02467, USA
| | - Kenneth S Burch
- Physics Department, Boston College, Boston, Massachusetts 02467, USA
| | - In-Sang Yang
- Department of Physics, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jaehong Jeong
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Je-Geun Park
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
- Center for Quantum Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - S J Moon
- Department of Physics, Hanyang University, Seoul 04763, Republic of Korea
| | - T W Noh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
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Kim SY, Kim TY, Sandilands LJ, Sinn S, Lee MC, Son J, Lee S, Choi KY, Kim W, Park BG, Jeon C, Kim HD, Park CH, Park JG, Moon SJ, Noh TW. Charge-Spin Correlation in van der Waals Antiferromagnet NiPS_{3}. Phys Rev Lett 2018; 120:136402. [PMID: 29694193 DOI: 10.1103/physrevlett.120.136402] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 09/29/2017] [Indexed: 06/08/2023]
Abstract
Strong charge-spin coupling is found in a layered transition-metal trichalcogenide NiPS_{3}, a van der Waals antiferromagnet, from studies of the electronic structure using several experimental and theoretical tools: spectroscopic ellipsometry, x-ray absorption, photoemission spectroscopy, and density functional calculations. NiPS_{3} displays an anomalous shift in the optical spectral weight at the magnetic ordering temperature, reflecting strong coupling between the electronic and magnetic structures. X-ray absorption, photoemission, and optical spectra support a self-doped ground state in NiPS_{3}. Our work demonstrates that layered transition-metal trichalcogenide magnets are useful candidates for the study of correlated-electron physics in two-dimensional magnetic materials.
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Affiliation(s)
- So Yeun Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Tae Yun Kim
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
- Center for Theoretical Physics, SNU, Seoul 08826, Republic of Korea
| | - Luke J Sandilands
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Soobin Sinn
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Min-Cheol Lee
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Jaeseok Son
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Sungmin Lee
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Ki-Young Choi
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Wondong Kim
- Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea
| | - Byeong-Gyu Park
- Pohang Accelerator Laboratory, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - C Jeon
- Advanced Nano-Surface Group, Korea Basic Science Institute (KBSI), Daejeon 34133, Republic of Korea
| | - Hyeong-Do Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Cheol-Hwan Park
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
- Center for Theoretical Physics, SNU, Seoul 08826, Republic of Korea
| | - Je-Geun Park
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - S J Moon
- Department of Physics, Hanyang University, Seoul 04763, Republic of Korea
| | - T W Noh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
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Sohn CH, Kim CH, Sandilands LJ, Hien NTM, Kim SY, Park HJ, Kim KW, Moon SJ, Yamaura J, Hiroi Z, Noh TW. Strong Spin-Phonon Coupling Mediated by Single Ion Anisotropy in the All-In-All-Out Pyrochlore Magnet Cd_{2}Os_{2}O_{7}. Phys Rev Lett 2017; 118:117201. [PMID: 28368646 DOI: 10.1103/physrevlett.118.117201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Indexed: 06/07/2023]
Abstract
Spin-phonon coupling mediated by single ion anisotropy was investigated using optical spectroscopy and first-principles calculations in the all-in-all-out pyrochlore magnet Cd_{2}Os_{2}O_{7}. Clear anomalies were observed in both the phonon frequencies and linewidths at the magnetic ordering temperature. The renormalization of the phonon modes was exceptionally large, signifying the presence of an unconventional magnetoelastic term from large spin-orbit coupling. In addition, the relative phonon frequency shifts show a strong correlation with the modulation of noncubic crystal field by the corresponding lattice distortion. Our observation establishes a new type of spin-phonon coupling through single ion anisotropy, a second-order spin-orbit coupling term, in Cd_{2}Os_{2}O_{7}.
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Affiliation(s)
- C H Sohn
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
| | - C H Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
| | - L J Sandilands
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
| | - N T M Hien
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
| | - S Y Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
| | - H J Park
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
| | - K W Kim
- Department of Physics, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - S J Moon
- Department of Physics, Hanyang University, Seoul 133-791, Republic of Korea
| | - J Yamaura
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - Z Hiroi
- ISSP, University of Tokyo, Kashiwa 277-8581, Japan
| | - T W Noh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Republic of Korea
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Sohn CH, Cho DY, Kuo CT, Sandilands LJ, Qi TF, Cao G, Noh TW. X-ray Absorption Spectroscopy Study of the Effect of Rh doping in Sr2IrO4. Sci Rep 2016; 6:23856. [PMID: 27025538 PMCID: PMC4812298 DOI: 10.1038/srep23856] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/16/2016] [Indexed: 11/16/2022] Open
Abstract
We investigate the effect of Rh doping in Sr2IrO4 using X-ray absorption spectroscopy (XAS). We observed appearance of new electron-addition states with increasing Rh concentration (x in Sr2Ir1-xRhxO4) in accordance with the concept of hole doping. The intensity of the hole-induced state is however weak, suggesting weakness of charge transfer (CT) effect and Mott insulating ground states. Also, Ir Jeff = 1/2 upper Hubbard band shifts to lower energy as x increases up to x = 0.23. Combined with optical spectroscopy, these results suggest a hybridisation-related mechanism, in which Rh doping can weaken the (Ir Jeff = 1/2)-(O 2p) orbital hybridisation in the in-planar Rh-O-Ir bond networks.
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Affiliation(s)
- C. H. Sohn
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - Deok-Yong Cho
- IPIT & Department of Physics, Chonbuk National University, Jeonju 54896, Korea
| | - C.-T. Kuo
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - L. J. Sandilands
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
| | - T. F. Qi
- Center for Advanced Materials, Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA
| | - G. Cao
- Center for Advanced Materials, Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA
| | - T. W. Noh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
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Sohn CH, Jeong H, Jin H, Kim S, Sandilands LJ, Park HJ, Kim KW, Moon SJ, Cho DY, Yamaura J, Hiroi Z, Noh TW. Optical Spectroscopic Studies of the Metal-Insulator Transition Driven by All-In-All-Out Magnetic Ordering in 5d Pyrochlore Cd(2)Os(2)O(7). Phys Rev Lett 2015; 115:266402. [PMID: 26765010 DOI: 10.1103/physrevlett.115.266402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Indexed: 06/05/2023]
Abstract
We investigated the metal-insulator transition (MIT) driven by all-in-all-out (AIAO) antiferromagnetic ordering in the 5d pyrochlore Cd(2)Os(2)O(7) using optical spectroscopy and first-principles calculations. We showed that the temperature evolution in the band-gap edge and free carrier density were consistent with rigid upward (downward) shifts of electron (hole) bands, similar to the case of Lifshitz transitions. The delicate relationship between the band gap and free carrier density provides experimental evidence for the presence of an AIAO metallic phase, a natural consequence of such MITs. The associated spectral weight change at high energy and first-principles calculations further support the origin of the MIT from the band shift near the Fermi level. Our data consistently support that the MIT induced by AIAO ordering in Cd(2)Os(2)O(7) is not close to a Slater type but instead to a Lifshitz type.
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Affiliation(s)
- C H Sohn
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - Hogyun Jeong
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Hosub Jin
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Soyeon Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - L J Sandilands
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - H J Park
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
| | - K W Kim
- Department of Physics, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - S J Moon
- Department of Physics, Hanyang University, Seoul 04763, Republic of Korea
| | - Deok-Yong Cho
- Department of Physics, Chonbuk National University, Jeonju 54896, Republic of Korea
| | - J Yamaura
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - Z Hiroi
- ISSP, University of Tokyo, Kashiwa 277-8581, Japan
| | - T W Noh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 08826, Republic of Korea
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Lee MC, Sohn CH, Kim SY, Lee KD, Won CJ, Hur N, Kim JY, Cho DY, Noh TW. Stabilization of ferromagnetic ordering in cobaltite double perovskites of La₂CoIrO₆ and La₂CoPtO₆. J Phys Condens Matter 2015; 27:336002. [PMID: 26235708 DOI: 10.1088/0953-8984/27/33/336002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We investigated the local electronic structure and magnetic properties of the cobaltite double perovskites La2CoIrO6 and La2CoPtO6 using Co L2,3-edge x-ray absorption spectroscopy and x-ray magnetic circular dichroism. Despite similarity in the local electronic structure (Co(2+) high-spin states) as well as in the crystal structure (P2(1)/n), only La2CoIrO6 exhibits substantial orbital and spin magnetic moments of Co(2+), whereas they are much weaker in the case of La2CoPtO6. This composition dependence is consistent with the results of magnetization measurements. The details of the mechanism of ferromagnetic ordering in the Co(2+) sublattice in La2CoIrO6 and the lack thereof in La2CoPtO6 are explained in terms of the orbital hybridization of the Co minority-spin t(2g) state and the Ir/Pt j(eff) = 1/2 state.
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Affiliation(s)
- Min-Cheol Lee
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul National University, Seoul 151-742, Korea. Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Korea
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Shin YJ, Jeon BC, Yang SM, Hwang I, Cho MR, Sando D, Lee SR, Yoon JG, Noh TW. Suppression of creep-regime dynamics in epitaxial ferroelectric BiFeO3 films. Sci Rep 2015; 5:10485. [PMID: 26014521 PMCID: PMC4444839 DOI: 10.1038/srep10485] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/13/2015] [Indexed: 12/05/2022] Open
Abstract
Switching dynamics of ferroelectric materials are governed by the response of domain walls to applied electric field. In epitaxial ferroelectric films, thermally-activated ‘creep’ motion plays a significant role in domain wall dynamics, and accordingly, detailed understanding of the system’s switching properties requires that this creep motion be taken into account. Despite this importance, few studies have investigated creep motion in ferroelectric films under ac-driven force. Here, we explore ac hysteretic dynamics in epitaxial BiFeO3 thin films, through ferroelectric hysteresis measurements, and stroboscopic piezoresponse force microscopy. We reveal that identically-fabricated BiFeO3 films on SrRuO3 or La0.67Sr0.33MnO3 bottom electrodes exhibit markedly different switching behaviour, with BiFeO3/SrRuO3 presenting essentially creep-free dynamics. This unprecedented result arises from the distinctive spatial inhomogeneities of the internal fields, these being influenced by the bottom electrode’s surface morphology. Our findings further highlight the importance of controlling interface and defect characteristics, to engineer ferroelectric devices with optimised performance.
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Affiliation(s)
- Y J Shin
- 1] Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea [2] Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
| | - B C Jeon
- 1] Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea [2] Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
| | - S M Yang
- 1] Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea [2] Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
| | - I Hwang
- Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea
| | - M R Cho
- Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
| | - D Sando
- 1] Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea [2] Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
| | - S R Lee
- 1] Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea [2] Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
| | - J-G Yoon
- Department of Physics, University of Suwon, Hawseong, Gyunggi-do 445-743, Republic of Korea
| | - T W Noh
- 1] Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-742, Republic of Korea [2] Department of Physics and Astronomy, Seoul National University (SNU), Seoul 151-742, Republic of Korea
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Jeong DW, Choi HC, Kim CH, Chang SH, Sohn CH, Park HJ, Kang TD, Cho DY, Baek SH, Eom CB, Shim JH, Yu J, Kim KW, Moon SJ, Noh TW. Temperature evolution of itinerant ferromagnetism in SrRuO3 probed by optical spectroscopy. Phys Rev Lett 2013; 110:247202. [PMID: 25165956 DOI: 10.1103/physrevlett.110.247202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Indexed: 06/03/2023]
Abstract
The temperature (T) dependence of the optical conductivity spectra σ(ω) of a single crystal SrRuO(3) thin film is studied over a T range from 5 to 450 K. We observed significant T dependence of the spectral weights of the charge transfer and interband d-d transitions across the ferromagnetic Curie temperature (T(c) ∼ 150 K). Such T dependence was attributed to the increase in the Ru spin moment, which is consistent with the results of density functional theory calculations. T scans of σ(Ω,T) at fixed frequencies Ω reveal a clear T(2) dependence below T(c), demonstrating that the Stoner mechanism is involved in the evolution of the electronic structure. In addition, σ(Ω,T) continues to evolve at temperatures above T(c), indicating that the local spin moment persists in the paramagnetic state. This suggests that SrRuO(3) is an intriguing oxide system with itinerant ferromagnetism.
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Affiliation(s)
- D W Jeong
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - Hong Chul Choi
- Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Choong H Kim
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - Seo Hyoung Chang
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - C H Sohn
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - H J Park
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - T D Kang
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - Deok-Yong Cho
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - S H Baek
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - C B Eom
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - J H Shim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - J Yu
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
| | - K W Kim
- Department of Physics, Chungbuk National University, Cheongju 361-763, Korea
| | - S J Moon
- Department of Physics, Hanyang University, Seoul 133-791, Korea
| | - T W Noh
- Center for Functional Interfaces of Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 151-747, Korea and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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Yin YW, Burton JD, Kim YM, Borisevich AY, Pennycook SJ, Yang SM, Noh TW, Gruverman A, Li XG, Tsymbal EY, Li Q. Enhanced tunnelling electroresistance effect due to a ferroelectrically induced phase transition at a magnetic complex oxide interface. Nat Mater 2013; 12:397-402. [PMID: 23416728 DOI: 10.1038/nmat3564] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 01/07/2013] [Indexed: 06/01/2023]
Abstract
The range of recently discovered phenomena in complex oxide heterostructures, made possible owing to advances in fabrication techniques, promise new functionalities and device concepts. One issue that has received attention is the bistable electrical modulation of conductivity in ferroelectric tunnel junctions (FTJs) in response to a ferroelectric polarization of the tunnelling barrier, a phenomenon known as the tunnelling electroresistance (TER) effect. Ferroelectric tunnel junctions with ferromagnetic electrodes allow ferroelectric control of the tunnelling spin polarization through the magnetoelectric coupling at the ferromagnet/ferroelectric interface. Here we demonstrate a significant enhancement of TER due to a ferroelectrically induced phase transition at a magnetic complex oxide interface. Ferroelectric tunnel junctions consisting of BaTiO3 tunnelling barriers and La(0.7)Sr(0.3)MnO3 electrodes exhibit a TER enhanced by up to ~10,000% by a nanometre-thick La(0.5)Ca(0.5)MnO3 interlayer inserted at one of the interfaces. The observed phenomenon originates from the metal-to-insulator phase transition in La(0.5)Ca(0.5)MnO3, driven by the modulation of carrier density through ferroelectric polarization switching. Electrical, ferroelectric and magnetoresistive measurements combined with first-principles calculations provide evidence for a magnetoelectric origin of the enhanced TER, and indicate the presence of defect-mediated conduction in the FTJs. The effect is robust and may serve as a viable route for electronic and spintronic applications.
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Lee SB, Yoo HK, Kim K, Lee JS, Kim YS, Sinn S, Lee D, Kang BS, Kahng B, Noh TW. Forming mechanism of the bipolar resistance switching in double-layer memristive nanodevices. Nanotechnology 2012; 23:315202. [PMID: 22802159 DOI: 10.1088/0957-4484/23/31/315202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
To initiate resistance switching phenomena, it is usually necessary to apply a strong electric field to a sample. This forming process poses very serious obstacles in real nanodevice applications. In unipolar resistance switching (URS), it is well known that the forming originates from soft dielectric breakdown. However, the forming in bipolar resistance switching (BRS) is poorly understood. In this study, we investigated the forming processes in Pt/Ta₂O₅/TaOx/Pt and Pt/TaOx/Pt nanodevices, which showed BRS and URS, respectively. By comparing the double- and single-layer systems, we were able to observe differences in the BRS and URS forming processes. Using computer simulations based on an 'interface-modified random circuit breaker network model', we could explain most of our experimental observations. This success suggests that the BRS forming in our Pt/Ta₂O₅/TaOx/Pt double-layer system can occur via two processes, i.e., polarity-dependent resistance switching in the Ta₂O₅ layer and soft dielectric breakdown in the TaOx layer. This forming mechanism can be used to improve the performance of BRS devices. For example, we could improve the endurance properties of Pt/Ta₂O₅/TaOx/Pt cells by using a small forming voltage.
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Affiliation(s)
- S B Lee
- IBS-Research Center for Functional Interfaces, Seoul National University, Seoul 151-747, Republic of Korea
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11
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Lee D, Yoon A, Jang SY, Yoon JG, Chung JS, Kim M, Scott JF, Noh TW. Giant flexoelectric effect in ferroelectric epitaxial thin films. Phys Rev Lett 2011; 107:057602. [PMID: 21867099 DOI: 10.1103/physrevlett.107.057602] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Indexed: 05/31/2023]
Abstract
We report on nanoscale strain gradients in ferroelectric HoMnO(3) epitaxial thin films, resulting in a giant flexoelectric effect. Using grazing-incidence in-plane x-ray diffraction, we measured strain gradients in the films, which were 6 or 7 orders of magnitude larger than typical values reported for bulk oxides. The combination of transmission electron microscopy, electrical measurements, and electrostatic calculations showed that flexoelectricity provides a means of tuning the physical properties of ferroelectric epitaxial thin films, such as domain configurations and hysteresis curves.
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Affiliation(s)
- D Lee
- ReCFI, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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12
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Abstract
AbstractEpitaxial magnetite (Fe3O4) thin films have been grown on MgO(001) substrates by pulsed laser deposition. The films have characteristics of the “Verwey transition”: the electric conductivity decreases by about one order of magnitude and the magnetization curve shows anomaly at the transition temperature, i.e. about 125 K. Effects of annealing the Fe3O4 thin films at various oxygen partial pressures have also been investigated. Phase identification was made using XRD techniques and infrared reflectivity measurements. The surface morphologies were studied by SEM and AFM. Under an oxidizing atmosphere, the Fe3O4 phase is transformed mainly into α-Fe2O3, and this transformation is accompanied by development of needle-like structures along <110> directions of MgO substrate. It is also found that electrical and magnetic properties of the iron oxide films are changed significantly by the annealing process.
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13
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Jang SY, Kim H, Moon SJ, Choi WS, Jeon BC, Yu J, Noh TW. The electronic structure of epitaxially stabilized 5d perovskite Ca(1-x)Sr(x)IrO3 (x = 0, 0.5, and 1) thin films: the role of strong spin-orbit coupling. J Phys Condens Matter 2010; 22:485602. [PMID: 21406751 DOI: 10.1088/0953-8984/22/48/485602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have investigated the electronic structure of meta-stable perovskite Ca(1 - x)Sr(x)IrO(3)(x = 0, 0.5, and 1) thin films using transport measurements, optical spectroscopy, and first-principles calculations. We artificially fabricated the perovskite phase of Ca(1 - x)Sr(x)IrO(3), which has a hexagonal or post-perovskite crystal structure in bulk form, by growing epitaxial thin films on perovskite GdScO(3) substrates using an epi-stabilization technique. The transport properties of the perovskite Ca(1 - x)Sr(x)IrO(3) films systematically change from nearly insulating (or semi-metallic) for x = 0 to weakly metallic for x = 1. Due to the extended wavefunctions, 5d electrons are usually delocalized. However, the strong spin-orbit coupling in Ca(1 - x)Sr(x)IrO(3) results in the formation of effective total angular momentum J(eff) = 1/2 and 3/2 states, which puts Ca(1 - x)Sr(x)IrO(3) in the vicinity of a metal-insulator phase boundary. As a result, the electrical properties of the Ca(1 - x)Sr(x)IrO(3) films are found to be sensitive to x and strain.
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Affiliation(s)
- S Y Jang
- ReCFI, Department of Physics and Astronomy, Seoul National University, Seoul, Republic of Korea
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14
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Lee JS, Lee SB, Chang SH, Gao LG, Kang BS, Lee MJ, Kim CJ, Noh TW, Kahng B. Scaling theory for unipolar resistance switching. Phys Rev Lett 2010; 105:205701. [PMID: 21231247 DOI: 10.1103/physrevlett.105.205701] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 10/04/2010] [Indexed: 05/30/2023]
Abstract
We investigate a reversible percolation system showing unipolar resistance switching in which percolating paths are created and broken alternately by the application of an electric bias. Owing to the dynamical changes in the percolating paths, different from those in classical percolating paths, a detailed understanding of the structure is demanding and challenging. Here, we develop a scaling theory that can explain the transport properties of these conducting paths; the theory is based on the fractal geometry of a percolating cluster. This theory predicts that two scaling behaviors emerge, depending on the topologies of the conducting paths. We confirm these theoretical predictions experimentally by observing material-independent universal scaling behaviors in unipolar resistance switching.
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Affiliation(s)
- J S Lee
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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15
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Jeon BC, Kim CH, Moon SJ, Choi WS, Jeong H, Lee YS, Yu J, Won CJ, Jung JH, Hur N, Noh TW. Electronic structure of double perovskite A2FeReO6 (A = Ba and Ca): interplay between spin-orbit interaction, electron correlation, and lattice distortion. J Phys Condens Matter 2010; 22:345602. [PMID: 21403258 DOI: 10.1088/0953-8984/22/34/345602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have investigated the electronic structure of double perovskites, Ba(2)FeReO(6) (metallic) and Ca(2)FeReO(6) (insulating) using optical and x-ray absorption spectroscopy. By comparing the experimental results with the density functional theory calculations, we found that the electronic structure of Ba(2)FeReO(6) could be determined from the interaction of the electron correlation and spin-orbit coupling. On the other hand, for Ca(2)FeReO(6), the lattice distortion and electron correlation are important in determining the electronic structure. Additionally, the insulating gap in Ca(2)FeReO(6) is realized by the spin-orbit coupling. Our work shows that the subtle interplay of the spin-orbit interaction, electron correlation, and lattice distortion should be taken into account to understand the electronic structure of the 5d transition metal oxides.
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Affiliation(s)
- B C Jeon
- ReCFI, Department of Physics and Astronomy, Seoul National University, Seoul, Korea
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16
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Seo SSA, Han MJ, Hassink GWJ, Choi WS, Moon SJ, Kim JS, Susaki T, Lee YS, Yu J, Bernhard C, Hwang HY, Rijnders G, Blank DHA, Keimer B, Noh TW. Two-dimensional confinement of 3d{1} electrons in LaTiO_{3}/LaAlO{3} multilayers. Phys Rev Lett 2010; 104:036401. [PMID: 20366664 DOI: 10.1103/physrevlett.104.036401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Indexed: 05/29/2023]
Abstract
We report spectroscopic ellipsometry measurements of the anisotropy of the interband transitions parallel and perpendicular to the planes of (LaTiO3)n(LaAlO3)5 multilayers with n=1-3. These provide direct information about the electronic structure of the two-dimensional (2D) 3d{1} state of the Ti ions. In combination with local density approximation, including a Hubbard U calculation, we suggest that 2D confinement in the TiO2 slabs lifts the degeneracy of the t{2g} states leaving only the planar d{xy} orbitals occupied. We outline that these multilayers can serve as a model system for the study of the t{2g} 2D Hubbard model.
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Affiliation(s)
- S S A Seo
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
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17
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Chang YJ, Kim CH, Phark SH, Kim YS, Yu J, Noh TW. Fundamental thickness limit of itinerant ferromagnetic SrRuO(3) thin films. Phys Rev Lett 2009; 103:057201. [PMID: 19792528 DOI: 10.1103/physrevlett.103.057201] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Indexed: 05/28/2023]
Abstract
We report on a fundamental thickness limit of the itinerant ferromagnetic oxide SrRuO(3) that might arise from the orbital-selective quantum confinement effects. Experimentally, SrRuO(3) films remain metallic even for a thickness of 2 unit cells (uc), but the Curie temperature T(C) starts to decrease at 4 uc and becomes zero at 2 uc. Using the Stoner model, we attributed the T(C) decrease to a decrease in the density of states (N(o)). Namely, in the thin film geometry, the hybridized Ru d(yz,zx) orbitals are terminated by top and bottom interfaces, resulting in quantum confinement and reduction of N(o).
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Affiliation(s)
- Young Jun Chang
- ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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18
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Jo JY, Yang SM, Kim TH, Lee HN, Yoon JG, Park S, Jo Y, Jung MH, Noh TW. Nonlinear dynamics of domain-wall propagation in epitaxial ferroelectric thin films. Phys Rev Lett 2009; 102:045701. [PMID: 19257442 DOI: 10.1103/physrevlett.102.045701] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 11/28/2008] [Indexed: 05/27/2023]
Abstract
We investigated the ferroelectric domain-wall propagation in epitaxial Pb(Zr,Ti)O3 thin film over a wide temperature range (3-300 K). We measured the domain-wall velocity under various electric fields and found that the velocity data is strongly nonlinear with electric fields, especially at low temperature. We found that, as one of surface growth issues, our domain-wall velocity data from ferroelectric epitaxial film could be classified into the creep, depinning, and flow regimes due to competition between disorder and elasticity. The measured values of velocity and dynamical exponents indicate that the ferroelectric domain walls in the epitaxial films are fractal and pinned by a disorder-induced local field.
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Affiliation(s)
- J Y Jo
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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19
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Chang SH, Lee JS, Chae SC, Lee SB, Liu C, Kahng B, Kim DW, Noh TW. Occurrence of both unipolar memory and threshold resistance switching in a NiO film. Phys Rev Lett 2009; 102:026801. [PMID: 19257301 DOI: 10.1103/physrevlett.102.026801] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Indexed: 05/03/2023]
Abstract
We observed two types of reversible resistance switching (RS) effects in a NiO film: memory RS at low temperature and threshold RS at high temperature. We were able to control the type of RS effects by thermal cycling. These phenomena were explained using a new dynamic percolation model that can describe the rupture and formation of conducting filaments. We showed that the RS effects are governed by the thermal stability of the filaments, which arise from competition between Joule heating and thermal dissipation. This work provides us understandings on basic mechanism of the RS effects and their interrelation.
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Affiliation(s)
- S H Chang
- ReCOE&FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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20
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Moon SJ, Jin H, Kim KW, Choi WS, Lee YS, Yu J, Cao G, Sumi A, Funakubo H, Bernhard C, Noh TW. Dimensionality-controlled insulator-metal transition and correlated metallic state in 5d transition metal oxides Sr n+1Ir nO3n+1 (n=1, 2, and infinity). Phys Rev Lett 2008; 101:226402. [PMID: 19113493 DOI: 10.1103/physrevlett.101.226402] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Indexed: 05/27/2023]
Abstract
We investigated the electronic structures of the 5d Ruddlesden-Popper series Sr n+1Ir nO3n+1 (n=1, 2, and infinity) using optical spectroscopy and first-principles calculations. As 5d orbitals are spatially more extended than 3d or 4d orbitals, it has been widely accepted that correlation effects are minimal in 5d compounds. However, we observed a Mott insulator-metal transition with a change of bandwidth as we increased n. In addition, the artificially synthesized perovskite SrIrO3 showed a very large mass enhancement of about 6, indicating that it was in a correlated metallic state.
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Affiliation(s)
- S J Moon
- ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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21
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Kim KW, Gu GD, Homes CC, Noh TW. Bound excitons in Sr2CuO3. Phys Rev Lett 2008; 101:177404. [PMID: 18999786 DOI: 10.1103/physrevlett.101.177404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Indexed: 05/27/2023]
Abstract
We investigated temperature dependent optical spectra of the one-dimensional chain compound Sr2CuO3. The charge transfer transition polarized along the chain direction shows a strongly asymmetric line shape as expected in one-dimensional extended Hubbard model. At low temperature, the charge transfer peak shows a large blueshift and reveals additional sharp peaks at the gap. Even though many spectroscopic studies suggest that this material cannot have a bound exciton based on the one-dimensional extended Hubbard model, we attribute the additional sharp peaks to excitons, which come to exist due to the long-range Coulomb interaction.
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Affiliation(s)
- K W Kim
- Department of Physics, University of Fribourg, Chemin du Muse 3, Fribourg, Switzerland.
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22
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Kim BJ, Jin H, Moon SJ, Kim JY, Park BG, Leem CS, Yu J, Noh TW, Kim C, Oh SJ, Park JH, Durairaj V, Cao G, Rotenberg E. Novel Jeff=1/2 Mott state induced by relativistic spin-orbit coupling in Sr2IrO4. Phys Rev Lett 2008; 101:076402. [PMID: 18764560 DOI: 10.1103/physrevlett.101.076402] [Citation(s) in RCA: 352] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Indexed: 05/23/2023]
Abstract
We investigated the electronic structure of 5d transition-metal oxide Sr2IrO4 using angle-resolved photoemission, optical conductivity, x-ray absorption measurements, and first-principles band calculations. The system was found to be well described by novel effective total angular momentum Jeff states, in which the relativistic spin-orbit coupling is fully taken into account under a large crystal field. Despite delocalized Ir 5d states, the Jeff states form such narrow bands that even a small correlation energy leads to the Jeff=1/2 Mott ground state with unique electronic and magnetic behaviors, suggesting a new class of Jeff quantum spin driven correlated-electron phenomena.
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Affiliation(s)
- B J Kim
- School of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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23
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Moon SJ, Choi WS, Kim SJ, Lee YS, Khalifah PG, Mandrus D, Noh TW. Orbital-driven electronic structure changes and the resulting optical anisotropy of the quasi-two-dimensional spin gap compound La4Ru2O10. Phys Rev Lett 2008; 100:116404. [PMID: 18517806 DOI: 10.1103/physrevlett.100.116404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Indexed: 05/26/2023]
Abstract
We investigated the electronic response of the quasi-two-dimensional spin gap compound La4Ru2O10 using optical spectroscopy. We observed the drastic changes in the optical spectra as the temperature decreased, resulting in anisotropy in the electronic structure of the spin-singlet ground state. Using the orbital-dependent hopping analysis, we found that orbital ordering plays a crucial role in forming the spin gap state in the non-one-dimensional material.
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Affiliation(s)
- S J Moon
- ReCOE and FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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24
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Jo JY, Han HS, Yoon JG, Song TK, Kim SH, Noh TW. Domain switching kinetics in disordered ferroelectric thin films. Phys Rev Lett 2007; 99:267602. [PMID: 18233604 DOI: 10.1103/physrevlett.99.267602] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Indexed: 05/25/2023]
Abstract
We investigated domain kinetics by measuring the polarization switching behaviors of (111)-preferred polycrystalline Pb(Zr,Ti)O3 films, which are widely used in ferroelectric memories. Their switching behaviors at various electric fields and temperatures could be explained by assuming the Lorentzian distribution of logarithmic domain-switching times. We suggested that the local field variation due to dipole defects at domain pinning sites could explain the Lorentzian distribution.
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Affiliation(s)
- J Y Jo
- ReCOE&FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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25
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Seo SSA, Choi WS, Lee HN, Yu L, Kim KW, Bernhard C, Noh TW. Optical study of the free-carrier response of LaTiO3/SrTiO3 superlattices. Phys Rev Lett 2007; 99:266801. [PMID: 18233598 DOI: 10.1103/physrevlett.99.266801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Indexed: 05/25/2023]
Abstract
We used infrared spectroscopic ellipsometry to investigate the electronic properties of LaTiO_{3}/SrTiO_{3} superlattices (SLs). Our results indicated that, independent of the SL periodicity and individual layer thickness, the SLs exhibited a Drude metallic response with sheet carrier density per interface approximately 3x10;{14} cm;{-2}. This is probably due to the leakage of d electrons at interfaces from the Mott insulator LaTiO3 to the band insulator SrTiO3. We observed a carrier relaxation time approximately 35 fs and mobility approximately 35 cm;{2} V-1 s;{-1} at 10 K, and an unusual temperature dependence of carrier density that was attributed to the dielectric screening of quantum paraelectric SrTiO3.
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Affiliation(s)
- S S A Seo
- ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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26
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Cho DY, Kim JY, Park BG, Rho KJ, Park JH, Noh HJ, Kim BJ, Oh SJ, Park HM, Ahn JS, Ishibashi H, Cheong SW, Lee JH, Murugavel P, Noh TW, Tanaka A, Jo T. Ferroelectricity driven by Y d0-ness with rehybridization in YMnO3. Phys Rev Lett 2007; 98:217601. [PMID: 17677806 DOI: 10.1103/physrevlett.98.217601] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Indexed: 05/16/2023]
Abstract
We investigated electronic structure of hexagonal multiferroic YMnO3 using the polarization dependent x-ray absorption spectroscopy (XAS) at O K and Mn L(2,3) edges. The spectra exhibit strong polarization dependence at both edges, reflecting anisotropic Mn 3d orbital occupation. Moreover, the O K edge spectra show that Y 4d states are strongly hybridized with O 2p ones, resulting in large anomalies in Born effective charges on off-centering Y and O ions. These results manifest that the Y d(0)-ness with rehybridization is the driving force for the ferroelectricity, and suggest a new approach to understand the multiferroicity in the hexagonal manganites.
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Affiliation(s)
- D-Y Cho
- CSCMR & School of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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27
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Kim MW, Lee HJ, Yang BJ, Kim KH, Moritomo Y, Yu J, Noh TW. Enhanced charge gap in the bilayer manganite La2-2xSr1+2xMn2O7 near x = 0.4. Phys Rev Lett 2007; 98:187201. [PMID: 17501603 DOI: 10.1103/physrevlett.98.187201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Indexed: 05/15/2023]
Abstract
We have investigated the optical conductivity spectra of La2-2xSr1+2xMn2O7 (0.3</=x</=0.5) systematically and found that for x near 0.4 the charge gap shows enhancement of up to approximately 0.3 eV just above the long-range magnetic ordering temperature. From comparison of this charge gap with other experimental results, we conclude that the peculiar x dependence of the charge gap cannot be understood in terms of the charge and lattice correlations only. We suggest that the unusual enhancement originates from the cooperative coupling between the short-range charge or lattice correlations and the quasi-one-dimensional energy band near the Fermi level.
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Affiliation(s)
- Myung Whun Kim
- ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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28
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Lee JS, Moon SJ, Yang BJ, Yu J, Schade U, Yoshida Y, Ikeda SI, Noh TW. Pseudogap dependence of the optical conductivity spectra of Ca3Ru2O7: a possible contribution of the orbital flip excitation. Phys Rev Lett 2007; 98:097403. [PMID: 17359196 DOI: 10.1103/physrevlett.98.097403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Indexed: 05/14/2023]
Abstract
Optical spectra of a double-layered perovskite ruthenate Ca3Ru2O7 show a pseudogap opening around 200 cm(-1) below 50 K, which is attributable to the partial k-space gap opening due to the density wave instability. Unlike most other density wave materials, Ca3Ru2O7 has spectral weight redistributions, not near the energy gap region, but at a much higher energy region around 800 cm(-1). As a possible origin of these intriguing features, we discuss the orbital flip excitation in the density wave ground state.
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Affiliation(s)
- J S Lee
- ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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29
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Jo JY, Kim DJ, Kim YS, Choe SB, Song TK, Yoon JG, Noh TW. Polarization switching dynamics governed by the thermodynamic nucleation process in ultrathin ferroelectric films. Phys Rev Lett 2006; 97:247602. [PMID: 17280324 DOI: 10.1103/physrevlett.97.247602] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Indexed: 05/13/2023]
Abstract
In most ferroelectrics, the domain nucleation barrier (U*) is thermally insurmountable; this is called "Landauer's paradox." However, we showed that, in ultrathin films, the large depolarization fields could lower U* to a level comparable to thermal energy (k(B)T), resulting in power-law decay of polarization. We empirically found a universal relation between the power-law decay exponent and U*/k(B)T. This relation will provide a practical but fundamental limit for capacitor-type ferroelectric devices, analogous to the superparamagnetic limit for magnetic memory devices.
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Affiliation(s)
- J Y Jo
- FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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30
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Kim MW, Moon SJ, Jung JH, Yu J, Parashar S, Murugavel P, Lee JH, Noh TW. Effect of orbital rotation and mixing on the optical properties of orthorhombic RMnO3 (R=La, Pr, Nd, Gd, and Tb). Phys Rev Lett 2006; 96:247205. [PMID: 16907278 DOI: 10.1103/physrevlett.96.247205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Indexed: 05/11/2023]
Abstract
We investigated the ab-plane absorption spectra of RMnO3 (R=La, Pr, Nd, Gd, and Tb) thin films. As the ionic radius of the R ion decreases, we observed a drastic suppression of the 2 eV peak, i.e., the intersite optical transition between spin- and orbital-aligned states across the Mott gap. We found that, in addition to orbital rotation, orbital mixing in the orbital-ordered state should play an important role in the suppression of 2 eV peak. We also found that the spectral weight of 2 eV peak is proportional to the A-type antiferromagnetic ordering temperature, which suggests that the magnetic interaction should be sensitively coupled to the orbital degree of freedom.
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Affiliation(s)
- M W Kim
- ReCOE & School of Physics, Seoul National University, Seoul 151-747, Korea
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Lee JS, Moon SJ, Noh TW, Nakatsuji S, Maeno Y. Orbital-selective mass enhancements in multiband Ca(2-x)Sr(x)RuO4 systems analyzed by the extended Drude model. Phys Rev Lett 2006; 96:057401. [PMID: 16486981 DOI: 10.1103/physrevlett.96.057401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 08/09/2005] [Indexed: 05/06/2023]
Abstract
We investigated optical spectra of quasi-two-dimensional multiband systems. The extended Drude model analysis on the -plane optical conductivity spectra indicates that the effective mass should be enhanced near . Based on the sum rule argument, we showed that the orbital-selective Mott-gap opening for the bands, the widely investigated picture, could not be the origin of the mass enhancement. We exploited the multiband effects in the extended Drude model analysis, and demonstrated that the intriguing heavy mass state near should come from the renormalization of the band.
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Affiliation(s)
- J S Lee
- ReCOE & School of Physics, Seoul National University, Seoul 151-747, Korea
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32
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Kim DJ, Jo JY, Kim YS, Chang YJ, Lee JS, Yoon JG, Song TK, Noh TW. Polarization relaxation induced by a depolarization field in ultrathin ferroelectric capacitors. Phys Rev Lett 2005; 95:237602. [PMID: 16384347 DOI: 10.1103/physrevlett.95.237602] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Indexed: 05/05/2023]
Abstract
Time-dependent polarization relaxation behavior induced by a depolarization field E(d) was investigated on high-quality ultrathin SrRuO3/BaTiO3/SrRuO3 capacitors. The E(d) values were determined experimentally from an applied external field to stop the net polarization relaxation. These values agree with those from the electrostatic calculations, demonstrating that a large E(d) inside the ultrathin ferroelectric layer could cause severe polarization relaxation. For numerous ferroelectric devices of capacitor configuration, this effect will set a stricter size limit than the critical thickness issue.
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Affiliation(s)
- D J Kim
- ReCOE and School of Physics, Seoul National University, Seoul 151-747, Korea
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33
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Kim TC, Ghim CM, Kim HJ, Kim DH, Noh DY, Kim ND, Chung JW, Yang JS, Chang YJ, Noh TW, Kahng B, Kim JS. Kinetic roughening of ion-sputtered Pd(001) surface: beyond the Kuramoto-Sivashinsky model. Phys Rev Lett 2004; 92:246104. [PMID: 15245109 DOI: 10.1103/physrevlett.92.246104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2003] [Revised: 02/10/2004] [Indexed: 05/24/2023]
Abstract
We investigate the kinetic roughening of Ar+ ion-sputtered Pd(001) surface both experimentally and theoretically. In situ real-time x-ray reflectivity and in situ scanning tunneling microscopy show that nanoscale adatom islands form and grow with increasing sputter time t. Surface roughness W(t) and lateral correlation length xi(t) follow the scaling laws W(t) approximately t(beta) and xi(t) approximately t(1/z) with the exponents beta approximately 0.20 and 1/z approximately 0.20, for an ion beam energy epsilon=0.5 keV, which is inconsistent with the prediction of the Kuramoto-Sivashinsky (KS) model. We thereby extend the KS model by applying the coarse-grained continuum approach of the Sigmund theory to the order of O(inverted Delta(4),h(2)), where h is the surface height, and derive a new term of the form inverted Delta(2)(inverted Delta h)(2) which plays a decisive role in describing the observed morphological evolution of the sputtered surface.
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Affiliation(s)
- T C Kim
- Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, 500-712, Korea
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34
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Kim YJ, Hill JP, Benthien H, Essler FHL, Jeckelmann E, Choi HS, Noh TW, Motoyama N, Kojima KM, Uchida S, Casa D, Gog T. Resonant inelastic X-ray scattering of the holon-antiholon continuum in SrCuO2. Phys Rev Lett 2004; 92:137402. [PMID: 15089644 DOI: 10.1103/physrevlett.92.137402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2003] [Indexed: 05/24/2023]
Abstract
We report a resonant inelastic x-ray scattering study of charge excitations in the quasi-one-dimensional Mott insulator SrCuO2. We observe a continuum of low-energy excitations, the onset of which exhibits a small dispersion of approximately 0.4 eV. Within this continuum, a highly dispersive feature with a large sinusoidal dispersion (approximately 1.1 eV) is observed. We have also measured the optical conductivity, and studied the dynamic response of the extended Hubbard model with realistic parameters, using a dynamical density-matrix renormalization group method. In contrast to earlier work, we do not find a long-lived exciton, but rather these results suggest that the excitation spectrum comprises a holon-antiholon continuum together with a broad resonance.
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Affiliation(s)
- Young-June Kim
- Department of Physics, Brookhaven National Laboratory, Upton, New York 11973, USA
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35
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Kim MW, Lee YS, Noh TW, Yu J, Moritomo Y. Optical-spectroscopic detection of spin-exchange interaction pyrochlore molybdates. Phys Rev Lett 2004; 92:027202. [PMID: 14753965 DOI: 10.1103/physrevlett.92.027202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Indexed: 05/24/2023]
Abstract
Optical spectroscopy was used to determine nearest-neighbor spin correlations in pyrochlore molybdates R2Mo2O7 (R=Y, Sm, and Nd), which exhibit ferromagnetic metal to spin-glass insulator transition as the R ion size decreases. Using an analysis based on the orbitally degenerate Hubbard model, we could estimate important physical parameters, such as the effective on-site Coulomb energy U(eff) and the Hund rule exchange coupling J(H). We demonstrated experimentally and theoretically that the effective superexchange interaction between the Mo ions depends on J(H)/U(eff), which determines the phase boundary of the magnetic ground states.
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Affiliation(s)
- M W Kim
- ReCOE & School of Physics, Seoul National University, Seoul 151-747, Korea
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36
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Lee JS, Lee YS, Noh TW, Oh SJ, Yu J, Nakatsuji S, Fukazawa H, Maeno Y. Electron and orbital correlations in Ca2-xSrxRuO4 probed by optical spectroscopy. Phys Rev Lett 2002; 89:257402. [PMID: 12484916 DOI: 10.1103/physrevlett.89.257402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2002] [Indexed: 05/24/2023]
Abstract
The optical conductivity spectra of the quasi-two-dimensional Ca2-xSrxRuO4 (0.0< or =x< or =2.0) system were investigated. In the Mott insulating state, two electron correlation-induced peaks were observed about 1.0 and 1.9 eV, which could be explained using the 3-orbital Hubbard model. The low frequency peak showed a shift toward higher frequency as temperature was lowered, indicating that electron-phonon interactions play an important role in the orbital arrangements. From the systematic analysis, it was suggested that the antiferro-orbital and the ferro-orbital ordering states could coexist.
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Affiliation(s)
- J S Lee
- School of Physics and Research Center for Oxide Electronics, Seoul National University, Korea
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Kim MW, Jung JH, Kim KH, Lee HJ, Yu J, Noh TW, Moritomo Y. Spin-orbital pattern dependent polaron absorption in manganites. Phys Rev Lett 2002; 89:016403. [PMID: 12097058 DOI: 10.1103/physrevlett.89.016403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2001] [Revised: 10/04/2001] [Indexed: 05/23/2023]
Abstract
We systematically investigated optical properties of Nd1-xSrxMnO3 single crystals ( x = 0.40, 0.50, 0.55, and 0.65). They are similar in their spin-orbital (SO) disordered states at room temperature. At low temperature, the crystals enter into various SO ordered states, i.e., F-, CE-, A-, and C-type orderings, and their mid-infrared absorptions become quite different. The remarkable variation can be explained by polaron dynamics which depend on the ordering patterns. This SO pattern dependent polaron model can also explain the pseudo CE-type ordering case, demonstrating that this scheme can explain the carrier dynamics in complex SO configurations.
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Affiliation(s)
- M W Kim
- School of Physics, Seoul National University, Seoul 151-747, Korea
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38
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Kim KH, Lee S, Noh TW, Cheong SW. Charge ordering fluctuation and optical pseudogap in La(1-x)Ca(x)MnO(3). Phys Rev Lett 2002; 88:167204. [PMID: 11955259 DOI: 10.1103/physrevlett.88.167204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2001] [Indexed: 05/23/2023]
Abstract
Optical spectroscopy was used to investigate the optical gap ( 2 Delta) due to charge ordering (CO) and related pseudogap developments with x and temperature ( T) in La(1-x)Ca(x)MnO(3) ( 0.48< or =x< or =0.67). Surprisingly, we found 2 Delta/k(B)T(CO) is as large as 30 for x approximately 0.5, and decreases rapidly with increasing x. Simultaneously, the optical pseudogap, possibly starting from T* far above T(CO) becomes drastically enhanced near x = 0.5, producing non-BCS T-dependence of 2 Delta with the large magnitude far above T(CO), and systematic increase of T* for x approximately 0.5. These results unequivocally indicate systematically enhanced CO correlation when x approaches 0.5 even though T(CO) decreases.
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Affiliation(s)
- K H Kim
- School of Physics, Seoul National University, Seoul 151-747, Korea
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Abstract
Thymoma with psuedosarcomatous stroma is a recently described, rare variant of thymomas that are characterized by having a biphasic histologic pattern which consists of both an epithelial and a spindle cell stromal component. So far only 11 cases having similar histologic findings have been reported worldwide. At this time we report a case of this rare variant of thymoma which occurred in a 53-year-old Korean man. This previously healthy patient presented with coughing and an anterior mediastinal mass was then detected radiographically. Mediastinal exploration revealed a 9 x 8 x 8 cm-sized well- encapsulated, ovoid, cystic mass. Histological examination showed a biphasic neoplasm composed of anastomosing nests of epithelial cells and somewhat cellular stromal spindle cells that had advanced degenerative changes. Immunohistochemical staining using the antibodies for cytokeratins, EMA, e-cadherin, and p75NGFR showed a strong expression of these markers in the epithelial component but no expression in the spindle stromal cells. The epithelial tumor cells showed no reactivity to CD5 and L26 and a high proportion of the infiltrated lymphocytes were the cortical type that expressed CD99 and terminal deoxynucleotidyl transferase. Ultrastructural examinations revealed tonofilaments in the spindle cells. Follow up has been done for 5 years after the surgical excision and the patient has been free of disease during that period. Similar to previous reports, this patient had a benign clinical course that was unassociated with myasthenia gravis which appears to be a characteristic of this histologic variant of thymoma. However, our case also showed advanced degenerative features and we could demonstrate ultrastructural evidence of epithelial differentiation in the stromal spindle cells that were not mentioned in the previously reported cases. Based on the results of our studies, we suggest this entity is a distinct type of organotypic thymoma that shows cortical differentiation and abundant cellular stroma.
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Affiliation(s)
- T W Noh
- Department of Pathology, Yonsei University College of Medicine, C.P.O. Box 8044, Seoul 120-752, Korea
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Abstract
Hepatoblastoma is the most common malignant hepatic neoplasm of childhood, showing a wide spectrum of epithelial and mesenchymal components. Teratoid hepatoblastoma, which reveals multiple lines of tissue differentiation such as mucinous epithelium, melanin pigment, endocrine differentiation, glial and mesenchymal components, has rarely been observed. We report a case of teratoid hepatoblastoma in a 22-month-old girl. She had been diagnosed with hepatoblastoma through percutaneous needle biopsy of the liver and treated with 10 chemotherapy cycles of epirubicin, VP-16 and cisplatin and with hepatic artery embolization. After 10 months, an extended left lobectomy was performed. Grossly, a multinodular, partly well-demarcated, solid mass (7 x 5 cm) with dense fibrosis and focal cystic change occupied almost the entire specimen. There was extensive necrosis due to preoperative treatment. Microscopically, the tumor showed multiple lines of differentiation, which was composed of embryonal, fetal hepatocytes and mesenchymal elements with numerous foci of osteoid. There were also other components showing endodermal, neural, melanocytic and endocrine differentiation. These teratoid components were considered relatively resistant to preoperative chemotherapy, in contrast to extensive necrosis of both embryonal and fetal hepatocytes. These teratoid features of hepatoblastoma are considered to be a multidirectional differentiation of the small epithelial cells or stem cells of the tumor.
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Affiliation(s)
- L Kim
- Department of Pathology, Yonsei University College of Medicine, C.P.O. Box 8044, Seoul 120-752, Korea
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Kim SH, Park YN, Yoon DS, Lee SJ, Yu JS, Noh TW. Composite neuroendocrine and adenocarcinoma of the common bile duct associated with Clonorchis sinensis: a case report. Hepatogastroenterology 2000; 47:942-4. [PMID: 11020854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The biliary tract has neuroendocrine cells of endoderm origin similar to the gastrointestinal tract, however neuroendocrine tumors of the biliary tract are rare. We report a composite glandular-endocrine cell carcinoma of the common bile duct in a 64-year-old Korean man which was associated with Clonorchis sinensis. The patient complained of right upper quadrant abdominal pain. Several parasites of Clonorchis sinensis were removed during the percutaneous transbiliary drainage. Endoscopic retrograde cholangiopancreatography revealed a polypoid mass (3 x 3 cm) with central ulceration in the common bile duct. Pancreaticoduodenectomy was performed. Microscopic examination of the tumor revealed a composite small cell neuroendocrine carcinoma and adenocarcinoma. The small cell carcinoma component showed positive reaction to chromogranin A and neuron-specific enolase and it was located mainly in the deeper portion of the mass. The well-differentiated adenocarcinoma component showed a positive reaction to carcinoembryonic antigen and it was situated in the superficial portion of the mass. Exclusively, the small cell component metastasized to the lymph node. It is suggested that this tumor could arise from a multipotential stem cell and showed neuroendocrine and glandular differentiation and that Clonorchis sinensis could be a predisposing factor, as in cholangiocarcinoma.
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Affiliation(s)
- S H Kim
- Department of Pathology, Yonsei University College of Medicine, Seoul, Korea
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Abstract
The initial presentation of breast malignancy as noninvasive carcinoma in an area of sclerosing adenosis is unusual. Especially, lobular carcinoma in situ in sclerosing adenosis sometimes can be a potential source of confusion with invasive lobular carcinoma. We report a case of lobular carcinoma in situ presenting in adenosis exhibiting patterns akin to invasive lobular carcinoma, thus leading to potential misdiagnosis. Overall architecture of the lesion as seen at lower power and immunohistochemistry can be useful to distinguish between sclerosing adenosis with lobular carcinoma in situ and infiltrating lobular carcinoma.
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Affiliation(s)
- W H Jung
- Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
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Lee YH, Yoo G, Jung HY, Hwang DH, Noh TW, Jeong HJ. Primary carcinoma of the fallopian tube coexisting with benign cystic teratoma of the ovary. Yonsei Med J 2000; 41:140-3. [PMID: 10731933 DOI: 10.3349/ymj.2000.41.1.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Primary carcinoma of the fallopian tube is a rare malignancy of the female genital tract and infrequently diagnosed before an operation. The majority of patients have extensive disease at the time of diagnosis. We have experienced incidentally a case of a carcinoma of the fallopian tube coexisting with a benign cystic teratoma of the ovary in a 25-year-old woman. We report this case with a brief review of literatures.
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Affiliation(s)
- Y H Lee
- Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Seoul, Korea.
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Kim KH, Gu JY, Choi HS, Park GW, Noh TW. Frequency Shifts of the Internal Phonon Modes in La0.7Ca0.3MnO3. Phys Rev Lett 1996; 77:1877-1880. [PMID: 10063194 DOI: 10.1103/physrevlett.77.1877] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Choi HS, Ahn JS, Jung JH, Noh TW, Kim DH. Mid-infrared properties of a VO2 film near the metal-insulator transition. Phys Rev B Condens Matter 1996; 54:4621-4628. [PMID: 9986420 DOI: 10.1103/physrevb.54.4621] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ahn JS, Choi HS, Noh TW. Infrared reflectance studies on a Fe3O4 film deposited on a MgO substrate: Observation of the substrate longitudinal optic phonon resonance peak in the film geometry. Phys Rev B Condens Matter 1996; 53:10310-10316. [PMID: 9982600 DOI: 10.1103/physrevb.53.10310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ahn JS, Kim KH, Noh TW, Riu DH, Boo KH, Kim HE. Effective-medium theories for spheroidal particles randomly oriented on a plane: Application to the optical properties of a SiC whisker-Al2O3 composite. Phys Rev B Condens Matter 1995; 52:15244-15252. [PMID: 9980879 DOI: 10.1103/physrevb.52.15244] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Noh TW, Song PH, Sievers AJ. Far-infrared sphere resonance in a polar semiconductor: A magneto-optical study of InSb particles. Phys Rev B Condens Matter 1993; 48:2320-2327. [PMID: 10008624 DOI: 10.1103/physrevb.48.2320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kaplan SG, Noh TW, Sievers AJ, Cheong SW, Fisk Z. Far-infrared antiferromagnetic resonance in Gd2CuO4. Phys Rev B Condens Matter 1993; 47:5300-5314. [PMID: 10006696 DOI: 10.1103/physrevb.47.5300] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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50
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Noh TW, Song PH, Lee SI, Harris DC, Gaines JR, Garland JC. Far-infrared studies of two-dimensional random metal-insulator composites. Phys Rev B Condens Matter 1992; 46:4212-4221. [PMID: 10004152 DOI: 10.1103/physrevb.46.4212] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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