1
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Ghiringhelli G. A noticeable absence. Nat Mater 2024; 23:443-444. [PMID: 38570633 DOI: 10.1038/s41563-024-01835-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
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2
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Martinelli L, Wohlfeld K, Pelliciari J, Arpaia R, Brookes NB, Di Castro D, Fernandez MG, Kang M, Krockenberger Y, Kummer K, McNally DE, Paris E, Schmitt T, Yamamoto H, Walters A, Zhou KJ, Braicovich L, Comin R, Sala MM, Devereaux TP, Daghofer M, Ghiringhelli G. Collective Nature of Orbital Excitations in Layered Cuprates in the Absence of Apical Oxygens. Phys Rev Lett 2024; 132:066004. [PMID: 38394564 DOI: 10.1103/physrevlett.132.066004] [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: 04/17/2023] [Revised: 10/27/2023] [Accepted: 12/21/2023] [Indexed: 02/25/2024]
Abstract
We have investigated the 3d orbital excitations in CaCuO_{2} (CCO), Nd_{2}CuO_{4} (NCO), and La_{2}CuO_{4} (LCO) using high-resolution resonant inelastic x-ray scattering. In LCO they behave as well-localized excitations, similarly to several other cuprates. On the contrary, in CCO and NCO the d_{xy} orbital clearly disperses, pointing to a collective character of this excitation (orbiton) in compounds without apical oxygen. We ascribe the origin of the dispersion as stemming from a substantial next-nearest-neighbor (NNN) orbital superexchange. Such an exchange leads to the liberation of the orbiton from its coupling to magnons, which is associated with the orbiton hopping between nearest neighbor copper sites. Finally, we show that the exceptionally large NNN orbital superexchange can be traced back to the absence of apical oxygens suppressing the charge transfer energy.
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Affiliation(s)
- Leonardo Martinelli
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Krzysztof Wohlfeld
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Pasteura 5, PL-02093 Warsaw, Poland
| | - Jonathan Pelliciari
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Riccardo Arpaia
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Nicholas B Brookes
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Daniele Di Castro
- Dipartimento di Ingegneria Civile e Ingegneria Informatica, Università di Roma Tor Vergata, Via del Politecnico 1, I-00133 Roma, Italy
- CNR-SPIN, Università di Roma Tor Vergata, Via del Politecnico 1, I-00133 Roma, Italy
| | | | - Mingu Kang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - Kurt Kummer
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Daniel E McNally
- Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Eugenio Paris
- Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Thorsten Schmitt
- Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Hideki Yamamoto
- NTT Basic Research Laboratories, NTT Corporation, Atsugi, Kanagawa, 243-0198, Japan
| | - Andrew Walters
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Ke-Jin Zhou
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Lucio Braicovich
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Riccardo Comin
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Marco Moretti Sala
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Thomas P Devereaux
- Stanford Institute for Materials and Energy Sciences, SLAC, Menlo Park, California 94025, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
| | - Maria Daghofer
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Giacomo Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
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3
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Arpaia R, Martinelli L, Sala MM, Caprara S, Nag A, Brookes NB, Camisa P, Li Q, Gao Q, Zhou X, Garcia-Fernandez M, Zhou KJ, Schierle E, Bauch T, Peng YY, Di Castro C, Grilli M, Lombardi F, Braicovich L, Ghiringhelli G. Signature of quantum criticality in cuprates by charge density fluctuations. Nat Commun 2023; 14:7198. [PMID: 37938250 PMCID: PMC10632404 DOI: 10.1038/s41467-023-42961-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/25/2023] [Indexed: 11/09/2023] Open
Abstract
The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where superconductivity hinders direct QCP observation, indirect evidence comes from the identification of fluctuations compatible with the strange metal phase. Here we show that the recently discovered charge density fluctuations (CDF) possess the right properties to be associated to a quantum phase transition. Using resonant x-ray scattering, we studied the CDF in two families of cuprate superconductors across a wide doping range (up to p = 0.22). At p* ≈ 0.19, the putative QCP, the CDF intensity peaks, and the characteristic energy Δ is minimum, marking a wedge-shaped region in the phase diagram indicative of a quantum critical behavior, albeit with anomalies. These findings strengthen the role of charge order in explaining strange metal phenomenology and provide insights into high-temperature superconductivity.
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Affiliation(s)
- Riccardo Arpaia
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296, Göteborg, Sweden.
| | - Leonardo Martinelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano, Italy
| | - Marco Moretti Sala
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano, Italy
| | - Sergio Caprara
- Dipartimento di Fisica, Università di Roma "La Sapienza", P.le Aldo Moro 5, I-00185, Roma, Italy
- CNR-ISC, via dei Taurini 19, I-00185, Roma, Italy
| | - Abhishek Nag
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - Nicholas B Brookes
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000, Grenoble, France
| | - Pietro Camisa
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano, Italy
| | - Qizhi Li
- International Center for Quantum Materials, School of Physics, Peking University, CN-100871, Beijing, China
| | - Qiang Gao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, CN-100190, Beijing, China
| | - Xingjiang Zhou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, CN-100190, Beijing, China
| | | | - Ke-Jin Zhou
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - Enrico Schierle
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, D-12489, Berlin, Germany
| | - Thilo Bauch
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296, Göteborg, Sweden
| | - Ying Ying Peng
- International Center for Quantum Materials, School of Physics, Peking University, CN-100871, Beijing, China
| | - Carlo Di Castro
- Dipartimento di Fisica, Università di Roma "La Sapienza", P.le Aldo Moro 5, I-00185, Roma, Italy
| | - Marco Grilli
- Dipartimento di Fisica, Università di Roma "La Sapienza", P.le Aldo Moro 5, I-00185, Roma, Italy
- CNR-ISC, via dei Taurini 19, I-00185, Roma, Italy
| | - Floriana Lombardi
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296, Göteborg, Sweden
| | - Lucio Braicovich
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano, Italy
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000, Grenoble, France
| | - Giacomo Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano, Italy.
- CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milano, Italy.
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4
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Krieger G, Martinelli L, Zeng S, Chow LE, Kummer K, Arpaia R, Moretti Sala M, Brookes NB, Ariando A, Viart N, Salluzzo M, Ghiringhelli G, Preziosi D. Charge and Spin Order Dichotomy in NdNiO_{2} Driven by the Capping Layer. Phys Rev Lett 2022; 129:027002. [PMID: 35867432 DOI: 10.1103/physrevlett.129.027002] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, with similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic and magnetic excitations and charge density correlations in Nd_{1-x}Sr_{x}NiO_{2} thin films with and without an SrTiO_{3} capping layer. We observe dispersing magnons only in the capped samples, progressively dampened at higher doping. We detect an elastic resonant scattering peak in the uncapped x=0 compound at wave vector (∼⅓,0), remindful of the charge order signal in hole doped cuprates. The peak weakens at x=0.05 and disappears in the superconducting x=0.20 film. The role of the capping on the electronic reconstruction far from the interface remains to be understood.
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Affiliation(s)
- G Krieger
- Université de Strasbourg, CNRS, IPCMS UMR 7504, F-67034 Strasbourg, France
| | - L Martinelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - S Zeng
- Department of Physics, Faculty of Science, National University of Singapore, 117551 Singapore, Singapore
| | - L E Chow
- Department of Physics, Faculty of Science, National University of Singapore, 117551 Singapore, Singapore
| | - K Kummer
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38043 Grenoble, France
| | - R Arpaia
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - M Moretti Sala
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - N B Brookes
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38043 Grenoble, France
| | - A Ariando
- Department of Physics, Faculty of Science, National University of Singapore, 117551 Singapore, Singapore
| | - N Viart
- Université de Strasbourg, CNRS, IPCMS UMR 7504, F-67034 Strasbourg, France
| | - M Salluzzo
- CNR-SPIN Complesso di Monte S. Angelo, via Cinthia-I-80126 Napoli, Italy
| | - G Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - D Preziosi
- Université de Strasbourg, CNRS, IPCMS UMR 7504, F-67034 Strasbourg, France
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5
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Wahlberg E, Arpaia R, Seibold G, Rossi M, Fumagalli R, Trabaldo E, Brookes NB, Braicovich L, Caprara S, Gran U, Ghiringhelli G, Bauch T, Lombardi F. Restored strange metal phase through suppression of charge density waves in underdoped YBa 2Cu 3O 7-δ. Science 2021; 373:1506-1510. [PMID: 34554788 DOI: 10.1126/science.abc8372] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Eric Wahlberg
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Riccardo Arpaia
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden.,Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - Götz Seibold
- Institut für Physik, BTU Cottbus-Senftenberg, D-03013 Cottbus, Germany
| | - Matteo Rossi
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - Roberto Fumagalli
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - Edoardo Trabaldo
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | | | - Lucio Braicovich
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy.,ESRF, European Synchrotron, F-38043 Grenoble, France
| | - Sergio Caprara
- Dipartimento di Fisica, Università di Roma "La Sapienza," I-00185 Roma, Italy.,CNR-ISC, I-00185 Roma, Italy
| | - Ulf Gran
- Division of Subatomic, High-Energy and Plasma Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Giacomo Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy.,CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - Thilo Bauch
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Floriana Lombardi
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
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6
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Geondzhian A, Sambri A, De Luca GM, Di Capua R, Di Gennaro E, Betto D, Rossi M, Peng YY, Fumagalli R, Brookes NB, Braicovich L, Gilmore K, Ghiringhelli G, Salluzzo M. Large Polarons as Key Quasiparticles in SrTiO_{3} and SrTiO_{3}-Based Heterostructures. Phys Rev Lett 2020; 125:126401. [PMID: 33016714 DOI: 10.1103/physrevlett.125.126401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/26/2020] [Accepted: 08/14/2020] [Indexed: 06/11/2023]
Abstract
Despite its simple structure and low degree of electronic correlation, SrTiO_{3} (STO) features collective phenomena linked to charge transport and, ultimately, superconductivity, that are not yet fully explained. Thus, a better insight into the nature of the quasiparticles shaping the electronic and conduction properties of STO is needed. We studied the low-energy excitations of bulk STO and of the LaAlO_{3}/SrTiO_{3} two-dimensional electron gas (2DEG) by Ti L_{3} edge resonant inelastic x-ray scattering. In all samples, we find the hallmark of polarons in the form of intense dd+phonon excitations, and a decrease of the LO3-mode electron-phonon coupling when going from insulating to highly conducting STO single crystals and heterostructures. Both results are attributed to the dynamic screening of the large polaron self-induced polarization, showing that the low-temperature physics of STO and STO-based 2DEGs is dominated by large polaron quasiparticles.
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Affiliation(s)
- Andrey Geondzhian
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Alessia Sambri
- CNR-SPIN Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
| | - Gabriella M De Luca
- CNR-SPIN Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
- Dipartimento di Fisica "Ettore Pancini" Università di Napoli "Federico II", Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
| | - Roberto Di Capua
- CNR-SPIN Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
- Dipartimento di Fisica "Ettore Pancini" Università di Napoli "Federico II", Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
| | - Emiliano Di Gennaro
- CNR-SPIN Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
- Dipartimento di Fisica "Ettore Pancini" Università di Napoli "Federico II", Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
| | - Davide Betto
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Matteo Rossi
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Ying Ying Peng
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- International Center for Quantum Materials,School of Physics, Peking University, Beijing 100871, China
| | - Roberto Fumagalli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Nicholas B Brookes
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Lucio Braicovich
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Keith Gilmore
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
- Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - Giacomo Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- CNR-SPIN, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Marco Salluzzo
- CNR-SPIN Complesso Monte-Santangelo via Cinthia, I-80126 Napoli, Italy
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7
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Arpaia R, Caprara S, Fumagalli R, De Vecchi G, Peng YY, Andersson E, Betto D, De Luca GM, Brookes NB, Lombardi F, Salluzzo M, Braicovich L, Di Castro C, Grilli M, Ghiringhelli G. Dynamical charge density fluctuations pervading the phase diagram of a Cu-based high- T c superconductor. Science 2020; 365:906-910. [PMID: 31467219 DOI: 10.1126/science.aav1315] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 07/30/2019] [Indexed: 11/02/2022]
Abstract
Charge density modulations have been observed in all families of high-critical temperature (T c) superconducting cuprates. Although they are consistently found in the underdoped region of the phase diagram and at relatively low temperatures, it is still unclear to what extent they influence the unusual properties of these systems. Using resonant x-ray scattering, we carefully determined the temperature dependence of charge density modulations in YBa2Cu3O7-δ and Nd1+ x Ba2- x Cu3O7-δ for several doping levels. We isolated short-range dynamical charge density fluctuations in addition to the previously known quasi-critical charge density waves. They persist up to well above the pseudogap temperature T*, are characterized by energies of a few milli-electron volts, and pervade a large area of the phase diagram.
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Affiliation(s)
- R Arpaia
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy. .,Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - S Caprara
- Dipartimento di Fisica, Università di Roma "La Sapienza," I-00185 Roma, Italy.,CNR-ISC, I-00185 Roma, Italy
| | - R Fumagalli
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - G De Vecchi
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - Y Y Peng
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - E Andersson
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - D Betto
- ESRF, European Synchrotron, F-38043 Grenoble, France
| | - G M De Luca
- Dipartimento di Fisica "E. Pancini," Università di Napoli Federico II, Complesso Monte Sant'Angelo, I-80126 Napoli, Italy.,CNR-SPIN, Complesso Monte Sant'Angelo, I-80126 Napoli, Italy
| | - N B Brookes
- ESRF, European Synchrotron, F-38043 Grenoble, France
| | - F Lombardi
- Quantum Device Physics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - M Salluzzo
- CNR-SPIN, Complesso Monte Sant'Angelo, I-80126 Napoli, Italy
| | - L Braicovich
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy.,ESRF, European Synchrotron, F-38043 Grenoble, France
| | - C Di Castro
- Dipartimento di Fisica, Università di Roma "La Sapienza," I-00185 Roma, Italy.,CNR-ISC, I-00185 Roma, Italy
| | - M Grilli
- Dipartimento di Fisica, Università di Roma "La Sapienza," I-00185 Roma, Italy.,CNR-ISC, I-00185 Roma, Italy
| | - G Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy. .,CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
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8
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Borgatti F, Pineider F, Sala MM, Minola M, Fantechi E, Ghiringhelli G, Brookes NB, Braicovich L, Sangregorio C. Resonant Inelastic Soft X-ray Scattering Study of Co-Doped Maghemite Nanoparticles. J Nanosci Nanotechnol 2019; 19:4980-4986. [PMID: 30913810 DOI: 10.1166/jnn.2019.16795] [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] [Indexed: 06/09/2023]
Abstract
Cobalt ferrite nanoparticles have been attracting considerable interest in the recent years because of the large number of potential applications, including magnetic storage, magnetic fluid hyperthermia and as contrast agents for magnetic resonance imaging. Physical properties of this class of materials depend critically on a number of parameters, including crystallinity, stoichiometry and cation distribution. In this work we have performed a Resonant Inelastic soft X-ray Scattering (RIXS) study on a series of 5 nm cobalt-doped maghemite nanoparticles to obtain direct quantitative information on cation distribution as a function of cobalt doping. We found that the distribution of divalent cobalt is stable in the investigated doping range and slightly different from that of bulk, stoichiometric cobalt ferrite. These results confirm that cobalt doping can be used to finely tune the magnetic properties of nanostructured ferrites without modifying their structural integrity.
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Affiliation(s)
- Francesco Borgatti
- Consiglio Nazionale delle Ricerche - Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), via P. Gobetti 101, 40129 Bologna, Italy
| | - Francesco Pineider
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via Moruzzi 13, 56124 Pisa, Italy
| | - Marco Moretti Sala
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - Matteo Minola
- Department of Solid State Spectroscopy, Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Elvira Fantechi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via Moruzzi 13, 56124 Pisa, Italy
| | - Giacomo Ghiringhelli
- Consiglio Nazionale delle Ricerche - SuPerconducting and Other INnovative Materials and Devices Institute (CNR-SPIN) and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano, I-20133, Italy
| | - Nicholas B Brookes
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - Lucio Braicovich
- Consiglio Nazionale delle Ricerche - SuPerconducting and Other INnovative Materials and Devices Institute (CNR-SPIN) and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano, I-20133, Italy
| | - Claudio Sangregorio
- Consiglio Nazionale delle Ricerche - SuPerconducting and Other INnovative Materials and Devices Institute (CNR-SPIN), via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy
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9
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Rossi M, Arpaia R, Fumagalli R, Moretti Sala M, Betto D, Kummer K, De Luca GM, van den Brink J, Salluzzo M, Brookes NB, Braicovich L, Ghiringhelli G. Experimental Determination of Momentum-Resolved Electron-Phonon Coupling. Phys Rev Lett 2019; 123:027001. [PMID: 31386544 DOI: 10.1103/physrevlett.123.027001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 06/10/2023]
Abstract
We provide a novel experimental method to quantitatively estimate the electron-phonon coupling and its momentum dependence from resonant inelastic x-ray scattering (RIXS) spectra based on the detuning of the incident photon energy away from an absorption resonance. We apply it to the cuprate parent compound NdBa_{2}Cu_{3}O_{6} and find that the electronic coupling to the oxygen half-breathing phonon branch is strongest at the Brillouin zone boundary, where it amounts to ∼0.17 eV, in agreement with previous studies. In principle, this method is applicable to any absorption resonance suitable for RIXS measurements and will help to define the contribution of lattice vibrations to the peculiar properties of quantum materials.
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Affiliation(s)
- Matteo Rossi
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Riccardo Arpaia
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Roberto Fumagalli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Marco Moretti Sala
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Davide Betto
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Kurt Kummer
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Gabriella M De Luca
- Dipartimento di Fisica "E. Pancini," Università degli Studi di Napoli "Federico II," Complesso Monte Sant'Angelo-Via Cinthia, I-80126 Napoli, Italy
- CNR-SPIN, Complesso Monte Sant'Angelo-Via Cinthia, I-80126 Napoli, Italy
| | - Jeroen van den Brink
- Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden, Germany
- Department of Physics, Technical University Dresden, D-01062 Dresden, Germany
| | - Marco Salluzzo
- CNR-SPIN, Complesso Monte Sant'Angelo-Via Cinthia, I-80126 Napoli, Italy
| | - Nicholas B Brookes
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Lucio Braicovich
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, CS 40220, F-38043 Grenoble, France
| | - Giacomo Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
- CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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10
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Hepting M, Chaix L, Huang EW, Fumagalli R, Peng YY, Moritz B, Kummer K, Brookes NB, Lee WC, Hashimoto M, Sarkar T, He JF, Rotundu CR, Lee YS, Greene RL, Braicovich L, Ghiringhelli G, Shen ZX, Devereaux TP, Lee WS. Three-dimensional collective charge excitations in electron-doped copper oxide superconductors. Nature 2018; 563:374-378. [PMID: 30429543 DOI: 10.1038/s41586-018-0648-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/22/2018] [Indexed: 11/09/2022]
Abstract
High-temperature copper oxide superconductors consist of stacked CuO2 planes, with electronic band structures and magnetic excitations that are primarily two-dimensional1,2, but with superconducting coherence that is three-dimensional. This dichotomy highlights the importance of out-of-plane charge dynamics, which has been found to be incoherent in the normal state3,4 within the limited range of momenta accessible by optics. Here we use resonant inelastic X-ray scattering to explore the charge dynamics across all three dimensions of the Brillouin zone. Polarization analysis of recently discovered collective excitations (modes) in electron-doped copper oxides5-7 reveals their charge origin, that is, without mixing with magnetic components5-7. The excitations disperse along both the in-plane and out-of-plane directions, revealing its three-dimensional nature. The periodicity of the out-of-plane dispersion corresponds to the distance between neighbouring CuO2 planes rather than to the crystallographic c-axis lattice constant, suggesting that the interplane Coulomb interaction is responsible for the coherent out-of-plane charge dynamics. The observed properties are hallmarks of the long-sought 'acoustic plasmon', which is a branch of distinct charge collective modes predicted for layered systems8-12 and argued to play a substantial part in mediating high-temperature superconductivity10-12.
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Affiliation(s)
- M Hepting
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA
| | - L Chaix
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Université Grenoble Alpes, CNRS, Institut Néel, Grenoble, France
| | - E W Huang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA
| | - R Fumagalli
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy
| | - Y Y Peng
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy.,Department of Physics and Seitz Materials Research Lab, University of Illinois, Urbana, IL, USA
| | - B Moritz
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA
| | - K Kummer
- European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - N B Brookes
- European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - W C Lee
- Department of Physics, Binghamton University, Binghamton, NY, USA
| | - M Hashimoto
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - T Sarkar
- Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD, USA
| | - J-F He
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Department of Physics, University of Science and Technology of China, Hefei, China
| | - C R Rotundu
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA
| | - Y S Lee
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA
| | - R L Greene
- Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD, USA
| | - L Braicovich
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy.,European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - G Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy.,CNR-SPIN, Politecnico di Milano, Milan, Italy
| | - Z X Shen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.
| | - T P Devereaux
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.
| | - W S Lee
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.
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11
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Peng YY, Fumagalli R, Ding Y, Minola M, Caprara S, Betto D, Bluschke M, De Luca GM, Kummer K, Lefrançois E, Salluzzo M, Suzuki H, Le Tacon M, Zhou XJ, Brookes NB, Keimer B, Braicovich L, Grilli M, Ghiringhelli G. Re-entrant charge order in overdoped (Bi,Pb) 2.12Sr 1.88CuO 6+δ outside the pseudogap regime. Nat Mater 2018; 17:697-702. [PMID: 29891891 DOI: 10.1038/s41563-018-0108-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Abstract
In the underdoped regime, the cuprate high-temperature superconductors exhibit a host of unusual collective phenomena, including unconventional spin and charge density modulations, Fermi surface reconstructions, and a pseudogap in various physical observables. Conversely, overdoped cuprates are generally regarded as conventional Fermi liquids possessing no collective electronic order. In partial contradiction to this widely held picture, we report resonant X-ray scattering measurements revealing incommensurate charge order reflections for overdoped (Bi,Pb)2.12Sr1.88CuO6+δ (Bi2201), with correlation lengths of 40-60 lattice units, that persist up to temperatures of at least 250 K. The value of the charge order wavevector decreases with doping, in line with the extrapolation of the trend previously observed in underdoped Bi2201. In overdoped materials, however, charge order coexists with a single, unreconstructed Fermi surface without nesting or pseudogap features. The discovery of re-entrant charge order in Bi2201 thus calls for investigations in other cuprate families and for a reconsideration of theories that posit an essential relationship between these phenomena.
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Affiliation(s)
- Y Y Peng
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- Department of Physics and Seitz Materials Research Laboratory, University of Illinois, Urbana, IL, USA
| | - R Fumagalli
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Y Ding
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - M Minola
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - S Caprara
- Dipartimento di Fisica, Università di Roma 'La Sapienza', Roma, Italy
- CNR-ISC, Roma, Italy
| | - D Betto
- ESRF, The European Synchrotron, Grenoble, France
| | - M Bluschke
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - G M De Luca
- Dipartimento di Fisica 'E. Pancini', Università di Napoli Federico II, Napoli, Italy
- CNR-SPIN, Napoli, Italy
| | - K Kummer
- ESRF, The European Synchrotron, Grenoble, France
| | - E Lefrançois
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | | | - H Suzuki
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - M Le Tacon
- Institute of Solid State Physics (IFP), Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - X J Zhou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - N B Brookes
- ESRF, The European Synchrotron, Grenoble, France
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
| | - L Braicovich
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
- ESRF, The European Synchrotron, Grenoble, France
| | - M Grilli
- Dipartimento di Fisica, Università di Roma 'La Sapienza', Roma, Italy
- CNR-ISC, Roma, Italy
| | - G Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy.
- CNR-SPIN, Dipartimento di Fisica, Politecnico di Milano, Milano, Italy.
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12
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Brookes NB, Ghiringhelli G, Glatzel P, Moretti Sala M. Resonant Inelastic X-ray Scattering at the ESRF: An Evolving Portfolio for Hard and Soft X-rays. ACTA ACUST UNITED AC 2018. [DOI: 10.1080/08940886.2018.1435953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
| | - G. Ghiringhelli
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy
- CNR-SPIN and CNISM, Politecnico di Milano, Milan, Italy
| | - P. Glatzel
- ESRF, The European Synchrotron, Grenoble, France
| | - M. Moretti Sala
- ESRF, The European Synchrotron, Grenoble, France
- Dipartimento di Fisica, Politecnico di Milano, Milan, Italy
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13
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Minola M, Lu Y, Peng YY, Dellea G, Gretarsson H, Haverkort MW, Ding Y, Sun X, Zhou XJ, Peets DC, Chauviere L, Dosanjh P, Bonn DA, Liang R, Damascelli A, Dantz M, Lu X, Schmitt T, Braicovich L, Ghiringhelli G, Keimer B, Le Tacon M. Crossover from Collective to Incoherent Spin Excitations in Superconducting Cuprates Probed by Detuned Resonant Inelastic X-Ray Scattering. Phys Rev Lett 2017; 119:097001. [PMID: 28949586 DOI: 10.1103/physrevlett.119.097001] [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: 10/17/2016] [Indexed: 06/07/2023]
Abstract
Spin excitations in the overdoped high temperature superconductors Tl_{2}Ba_{2}CuO_{6+δ} and (Bi,Pb)_{2}(Sr,La)_{2}CuO_{6+δ} were investigated by resonant inelastic x-ray scattering (RIXS) as functions of doping and detuning of the incoming photon energy above the Cu-L_{3} absorption peak. The RIXS spectra at optimal doping are dominated by a paramagnon feature with peak energy independent of photon energy, similar to prior results on underdoped cuprates. Beyond optimal doping, the RIXS data indicate a sharp crossover to a regime with a strong contribution from incoherent particle-hole excitations whose maximum shows a fluorescencelike shift upon detuning. The spectra of both compound families are closely similar, and their salient features are reproduced by exact-diagonalization calculations of the single-band Hubbard model on a finite cluster. The results are discussed in the light of recent transport experiments indicating a quantum phase transition near optimal doping.
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Affiliation(s)
- M Minola
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Y Lu
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Y Y Peng
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - G Dellea
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - H Gretarsson
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - M W Haverkort
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Strasse 40, 01187 Dresden, Germany and Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, 69120 Heidelberg, Germany
| | - Y Ding
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - X Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - X J Zhou
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - D C Peets
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - L Chauviere
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - P Dosanjh
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - D A Bonn
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - R Liang
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - A Damascelli
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - M Dantz
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - X Lu
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - T Schmitt
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - L Braicovich
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - G Ghiringhelli
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - M Le Tacon
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
- Institut für Festkörperphysik, Karlsruher Institut für Technologie, Hermann-v.-Helmoltz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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14
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Kummer K, Tamborrino A, Amorese A, Minola M, Braicovich L, Brookes NB, Ghiringhelli G. RixsToolBox: software for the analysis of soft X-ray RIXS data acquired with 2D detectors. J Synchrotron Radiat 2017; 24:531-536. [PMID: 28244450 DOI: 10.1107/s1600577517000832] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/17/2017] [Indexed: 06/06/2023]
Abstract
A software with a graphical user interface has been developed with the aim of facilitating the data analysis for users of a new resonant inelastic X-ray scattering (RIXS) spectrometer installed at the ESRF beamline ID32. The software is organized in modules covering all relevant steps in the data reduction from a stack of several hundred two-dimensional CCD images to a single RIXS spectrum. It utilizes both full charge integration and single-photon centroiding to cope with high-flux and high-resolution requirements. Additional modules for further data analysis and the extraction of instrumental parameters are available. The software has been in routine use for about a year now and in that time many additional features have been incorporated. It now meets the users' need for an easy-to-use data analysis tool that allows looking at and understanding data as it is acquired and thus steering users' experiments more efficiently.
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Affiliation(s)
- K Kummer
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS40220, F-38043 Grenoble Cedex 9, France
| | - A Tamborrino
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS40220, F-38043 Grenoble Cedex 9, France
| | - A Amorese
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS40220, F-38043 Grenoble Cedex 9, France
| | - M Minola
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - L Braicovich
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - N B Brookes
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS40220, F-38043 Grenoble Cedex 9, France
| | - G Ghiringhelli
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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15
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Stornaiuolo D, Cantoni C, De Luca GM, Di Capua R, Di Gennaro E, Ghiringhelli G, Jouault B, Marrè D, Massarotti D, Miletto Granozio F, Pallecchi I, Piamonteze C, Rusponi S, Tafuri F, Salluzzo M. Tunable spin polarization and superconductivity in engineered oxide interfaces. Nat Mater 2016; 15:278-283. [PMID: 26641020 DOI: 10.1038/nmat4491] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 10/16/2015] [Indexed: 06/05/2023]
Abstract
Advances in growth technology of oxide materials allow single atomic layer control of heterostructures. In particular delta doping, a key materials' engineering tool in today's semiconductor technology, is now also available for oxides. Here we show that a fully electric-field-tunable spin-polarized and superconducting quasi-2D electron system (q2DES) can be artificially created by inserting a few unit cells of delta doping EuTiO3 at the interface between LaAlO3 and SrTiO3 oxides. Spin polarization emerges below the ferromagnetic transition temperature of the EuTiO3 layer (TFM = 6-8 K) and is due to the exchange interaction between the magnetic moments of Eu-4f and of Ti-3d electrons. Moreover, in a large region of the phase diagram, superconductivity sets in from a ferromagnetic normal state. The occurrence of magnetic interactions, superconductivity and spin-orbit coupling in the same q2DES makes the LaAlO3/EuTiO3/SrTiO3 system an intriguing platform for the emergence of novel quantum phases in low-dimensional materials.
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Affiliation(s)
- D Stornaiuolo
- Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
| | - C Cantoni
- Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - G M De Luca
- Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
| | - R Di Capua
- Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
| | - E Di Gennaro
- Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
| | - G Ghiringhelli
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - B Jouault
- Laboratoire Charles Coulomb, UMR 5221, CNRS, Université Montpellier 2, F-34095 Montpellier, France
| | - D Marrè
- CNR-SPIN and Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, I-14146 Genova, Italy
| | - D Massarotti
- Dipartimento di Fisica, Università di Napoli "Federico II", Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
| | - F Miletto Granozio
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
| | - I Pallecchi
- CNR-SPIN and Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, I-14146 Genova, Italy
| | - C Piamonteze
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - S Rusponi
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - F Tafuri
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
- Dipartimento di Ingegneria dell'Informazione, Seconda Università degli Studi di Napoli (SUN), 81031 Aversa (CE), Italy
| | - M Salluzzo
- CNR-SPIN, Complesso Monte Sant'Angelo via Cinthia, I-80126 Napoli, Italy
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16
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Minola M, Dellea G, Gretarsson H, Peng YY, Lu Y, Porras J, Loew T, Yakhou F, Brookes NB, Huang YB, Pelliciari J, Schmitt T, Ghiringhelli G, Keimer B, Braicovich L, Le Tacon M. Collective nature of spin excitations in superconducting cuprates probed by resonant inelastic X-ray scattering. Phys Rev Lett 2015; 114:217003. [PMID: 26066453 DOI: 10.1103/physrevlett.114.217003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Indexed: 06/04/2023]
Abstract
We used resonant inelastic x-ray scattering (RIXS) with and without analysis of the scattered photon polarization, to study dispersive spin excitations in the high temperature superconductor YBa_{2}Cu_{3}O_{6+x} over a wide range of doping levels (0.1≤x≤1). The excitation profiles were carefully monitored as the incident photon energy was detuned from the resonant condition, and the spin excitation energy was found to be independent of detuning for all x. These findings demonstrate that the largest fraction of the spin-flip RIXS profiles in doped cuprates arises from magnetic collective modes, rather than from incoherent particle-hole excitations as recently suggested theoretically [Benjamin et al. Phys. Rev. Lett. 112, 247002 (2014)]. Implications for the theoretical description of the electron system in the cuprates are discussed.
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Affiliation(s)
- M Minola
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - G Dellea
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - H Gretarsson
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Y Y Peng
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - Y Lu
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - J Porras
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - T Loew
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - F Yakhou
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - N B Brookes
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - Y B Huang
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J Pelliciari
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - T Schmitt
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - G Ghiringhelli
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - L Braicovich
- CNISM, CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - M Le Tacon
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
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17
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Tabis W, Li Y, Le Tacon M, Braicovich L, Kreyssig A, Minola M, Dellea G, Weschke E, Veit MJ, Ramazanoglu M, Goldman AI, Schmitt T, Ghiringhelli G, Barišić N, Chan MK, Dorow CJ, Yu G, Zhao X, Keimer B, Greven M. Charge order and its connection with Fermi-liquid charge transport in a pristine high-T(c) cuprate. Nat Commun 2014; 5:5875. [PMID: 25522689 DOI: 10.1038/ncomms6875] [Citation(s) in RCA: 236] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 11/17/2014] [Indexed: 11/09/2022] Open
Abstract
Electronic inhomogeneity appears to be an inherent characteristic of the enigmatic cuprate superconductors. Here we report the observation of charge-density-wave correlations in the model cuprate superconductor HgBa2CuO(4+δ) (T(c)=72 K) via bulk Cu L3-edge-resonant X-ray scattering. At the measured hole-doping level, both the short-range charge modulations and Fermi-liquid transport appear below the same temperature of about 200 K. Our result points to a unifying picture in which these two phenomena are preceded at the higher pseudogap temperature by q=0 magnetic order and the build-up of significant dynamic antiferromagnetic correlations. The magnitude of the charge modulation wave vector is consistent with the size of the electron pocket implied by quantum oscillation and Hall effect measurements for HgBa2CuO(4+δ) and with corresponding results for YBa2Cu3O(6+δ), which indicates that charge-density-wave correlations are universally responsible for the low-temperature quantum oscillation phenomenon.
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Affiliation(s)
- W Tabis
- 1] School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA [2] AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Al. Mickiewicza 30, 30-059 Krakow, Poland
| | - Y Li
- 1] International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China [2] Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - M Le Tacon
- Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - L Braicovich
- CNR-SPIN, CNISM and Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - A Kreyssig
- Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - M Minola
- Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - G Dellea
- CNR-SPIN, CNISM and Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - E Weschke
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - M J Veit
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - M Ramazanoglu
- 1] Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA [2] Physics Engineering Department, ITU, Maslak 34469, Istanbul, Turkey
| | - A I Goldman
- Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - T Schmitt
- Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - G Ghiringhelli
- CNR-SPIN, CNISM and Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
| | - N Barišić
- 1] School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA [2] Service de Physique de l'Etat Condensé, CEA-DSM-IRAMIS, F-91198 Gif-sur-Yvette, France [3] Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
| | - M K Chan
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - C J Dorow
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - G Yu
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - X Zhao
- 1] School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA [2] State Key Lab of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
| | - B Keimer
- Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany
| | - M Greven
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
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18
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Braicovich L, Minola M, Dellea G, Le Tacon M, Moretti Sala M, Morawe C, Peffen JC, Supruangnet R, Yakhou F, Ghiringhelli G, Brookes NB. The simultaneous measurement of energy and linear polarization of the scattered radiation in resonant inelastic soft x-ray scattering. Rev Sci Instrum 2014; 85:115104. [PMID: 25430146 DOI: 10.1063/1.4900959] [Citation(s) in RCA: 3] [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] [Indexed: 05/23/2023]
Abstract
Resonant Inelastic X-ray Scattering (RIXS) in the soft x-ray range is an element-specific energy-loss spectroscopy used to probe the electronic and magnetic excitations in strongly correlated solids. In the recent years, RIXS has been progressing very quickly in terms of energy resolution and understanding of the experimental results, but the interpretation of spectra could further improve, sometimes decisively, from a full knowledge of the polarization of incident and scattered photons. Here we present the first implementation, in a high resolution soft-RIXS spectrometer used to analyze the scattered radiation, of a device allowing the measurement of the degree of linear polarization. The system, based on a graded W/B4C multilayer mirror installed in proximity of the CCD detector, has been installed on the AXES spectrometer at the ESRF (European Synchrotron Radiation Facility); it has been fully characterized and it has been used for a demonstration experiment at the Cu L3 edge on a high-Tc superconducting cuprate. The loss in efficiency suffered by the spectrometer equipped with this test facility was a factor 17.5. We propose also a more advanced version, suitable for a routine use on the next generation of RIXS spectrometers and with an overall efficiency up to 10%.
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Affiliation(s)
- L Braicovich
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133, Italy
| | - M Minola
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133, Italy
| | - G Dellea
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133, Italy
| | - M Le Tacon
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - M Moretti Sala
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - C Morawe
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - J-Ch Peffen
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - R Supruangnet
- Synchrotron Light Research Institute, Nakhon Ratchasima, Thailand
| | - F Yakhou
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
| | - G Ghiringhelli
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133, Italy
| | - N B Brookes
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043, France
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19
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Ishii K, Fujita M, Sasaki T, Minola M, Dellea G, Mazzoli C, Kummer K, Ghiringhelli G, Braicovich L, Tohyama T, Tsutsumi K, Sato K, Kajimoto R, Ikeuchi K, Yamada K, Yoshida M, Kurooka M, Mizuki J. High-energy spin and charge excitations in electron-doped copper oxide superconductors. Nat Commun 2014; 5:3714. [PMID: 24762677 DOI: 10.1038/ncomms4714] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 03/24/2014] [Indexed: 11/09/2022] Open
Abstract
The evolution of electronic (spin and charge) excitations upon carrier doping is an extremely important issue in superconducting layered cuprates and the knowledge of its asymmetry between electron- and hole-dopings is still fragmentary. Here we combine X-ray and neutron inelastic scattering measurements to track the doping dependence of both spin and charge excitations in electron-doped materials. Copper L3 resonant inelastic X-ray scattering spectra show that magnetic excitations shift to higher energy upon doping. Their dispersion becomes steeper near the magnetic zone centre and they deeply mix with charge excitations, indicating that electrons acquire a highly itinerant character in the doped metallic state. Moreover, above the magnetic excitations, an additional dispersing feature is observed near the Γ-point, and we ascribe it to particle-hole charge excitations. These properties are in stark contrast with the more localized spin excitations (paramagnons) recently observed in hole-doped compounds even at high doping levels.
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Affiliation(s)
- K Ishii
- SPring-8, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148, Japan
| | - M Fujita
- Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
| | - T Sasaki
- Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
| | - M Minola
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, Milano I-20133, Italy
| | - G Dellea
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, Milano I-20133, Italy
| | - C Mazzoli
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, Milano I-20133, Italy
| | - K Kummer
- European Synchrotron Radiation Facility, 6 rue Jules Horowitz, Grenoble F-38043, France
| | - G Ghiringhelli
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, Milano I-20133, Italy
| | - L Braicovich
- CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, Milano I-20133, Italy
| | - T Tohyama
- 1] Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan [2]
| | - K Tsutsumi
- Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
| | - K Sato
- Institute for Materials Research, Tohoku University, Katahira, Sendai 980-8577, Japan
| | - R Kajimoto
- Materials and Life Science Division, J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - K Ikeuchi
- Research Center for Neutron Science and Technology, Comprehensive Research Organization for Science and Society, Tokai, Ibaraki 319-1106, Japan
| | - K Yamada
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan
| | - M Yoshida
- 1] SPring-8, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148, Japan [2] School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - M Kurooka
- School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - J Mizuki
- 1] SPring-8, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148, Japan [2] School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
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20
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Ilakovac V, Guarise M, Grioni M, Schmitt T, Zhou K, Braicovich L, Ghiringhelli G, Strocov VN, Berger H. Opening of a Peierls gap in BaVS3 probed by V L3 edge resonant inelastic x-ray scattering. J Phys Condens Matter 2013; 25:505602. [PMID: 24275702 DOI: 10.1088/0953-8984/25/50/505602] [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] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
V L3 edge resonant inelastic x-ray scattering measurements performed on high quality BaVS3 single crystals reveal that the intra-t2g dd excitations close to the elastic peak are suppressed below the metal-insulator transition induced by the Peierls instability. The depletion of electronic states close to the Fermi level represents a direct observation of the opening of a charge gap inside the t2g manifold.
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Affiliation(s)
- V Ilakovac
- Université Pierre et Marie Curie, CNRS UMR 7614, LCP-MR, F-75231 Paris, France. Université de Cergy-Pontoise, F-95031 Cergy-Pontoise, France
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21
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Dean MPM, Dellea G, Springell RS, Yakhou-Harris F, Kummer K, Brookes NB, Liu X, Sun YJ, Strle J, Schmitt T, Braicovich L, Ghiringhelli G, Božović I, Hill JP. Persistence of magnetic excitations in La(2-x)Sr(x)CuO4 from the undoped insulator to the heavily overdoped non-superconducting metal. Nat Mater 2013; 12:1019-23. [PMID: 23913170 DOI: 10.1038/nmat3723] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 06/26/2013] [Indexed: 05/23/2023]
Abstract
One of the most intensely studied scenarios of high-temperature superconductivity (HTS) postulates pairing by exchange of magnetic excitations. Indeed, such excitations have been observed up to optimal doping in the cuprates. In the heavily overdoped regime, neutron scattering measurements indicate that magnetic excitations have effectively disappeared, and this has been argued to cause the demise of HTS with overdoping. Here we use resonant inelastic X-ray scattering, which is sensitive to complementary parts of reciprocal space, to measure the evolution of the magnetic excitations in La(2-x)Sr(x)CuO4 across the entire phase diagram, from a strongly correlated insulator (x = 0) to a non-superconducting metal (x = 0.40). For x = 0, well-defined magnon excitations are observed. These magnons broaden with doping, but they persist with a similar dispersion and comparable intensity all the way to the non-superconducting, heavily overdoped metallic phase. The destruction of HTS with overdoping is therefore caused neither by the general disappearance nor by the overall softening of magnetic excitations. Other factors, such as the redistribution of spectral weight, must be considered.
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Affiliation(s)
- M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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22
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Salluzzo M, Gariglio S, Stornaiuolo D, Sessi V, Rusponi S, Piamonteze C, De Luca GM, Minola M, Marré D, Gadaleta A, Brune H, Nolting F, Brookes NB, Ghiringhelli G. Origin of interface magnetism in BiMnO3/SrTiO3 and LaAlO3/SrTiO3 heterostructures. Phys Rev Lett 2013; 111:087204. [PMID: 24010471 DOI: 10.1103/physrevlett.111.087204] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Indexed: 06/02/2023]
Abstract
Possible ferromagnetism induced in otherwise nonmagnetic materials has been motivating intense research in complex oxide heterostructures. Here we show that a confined magnetism is realized at the interface between SrTiO3 and two insulating polar oxides, BiMnO3 and LaAlO3. By using polarization dependent x-ray absorption spectroscopy, we find that in both cases the magnetism can be stabilized by a negative exchange interaction between the electrons transferred to the interface and local magnetic moments. These local magnetic moments are associated with magnetic Ti3+ ions at the interface itself for LaAlO3/SrTiO3 and to Mn3+ ions in the overlayer for BiMnO3/SrTiO3. In LaAlO3/SrTiO3 the induced magnetism is quenched by annealing in oxygen, suggesting a decisive role of oxygen vacancies in this phenomenon.
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Affiliation(s)
- M Salluzzo
- CNR-SPIN, Complesso MonteSantangelo via Cinthia, I-80126 Napoli, Italy
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23
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Blanco-Canosa S, Frano A, Loew T, Lu Y, Porras J, Ghiringhelli G, Minola M, Mazzoli C, Braicovich L, Schierle E, Weschke E, Le Tacon M, Keimer B. Momentum-dependent charge correlations in YBa2Cu3O6+δ superconductors probed by resonant X-ray scattering: evidence for three competing phases. Phys Rev Lett 2013; 110:187001. [PMID: 23683237 DOI: 10.1103/physrevlett.110.187001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Indexed: 06/02/2023]
Abstract
We use resonant x-ray scattering to determine the momentum-dependent charge correlations in YBa(2)Cu(3) O(6.55) samples with highly ordered chain arrays of oxygen acceptors (ortho-II structure). The results reveal nearly critical, biaxial charge density wave (CDW) correlations at in-plane wave vectors (0.315, 0) and (0, 0.325). The corresponding scattering intensity exhibits a strong uniaxial anisotropy. The CDW amplitude and correlation length are enhanced as superconductivity is weakened by an external magnetic field. Analogous experiments are carried out on a YBa(2)Cu(3)O(6.6) crystal with a dilute concentration of spinless (Zn) impurities, which had earlier been shown to nucleate incommensurate magnetic order. Compared to pristine crystals with the same doping level, the CDW amplitude and correlation length are found to be strongly reduced. These results indicate a three-phase competition between spin-modulated, charge-modulated, and superconducting states in underdoped YBa(2)Cu(3)O(6+δ).
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Affiliation(s)
- S Blanco-Canosa
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
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24
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Salluzzo M, Gariglio S, Torrelles X, Ristic Z, Di Capua R, Drnec J, Sala MM, Ghiringhelli G, Felici R, Brookes NB. Structural and electronic reconstructions at the LaAlO₃/SrTiO₃ interface. Adv Mater 2013; 25:2333-2332. [PMID: 23382034 DOI: 10.1002/adma.201204555] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/17/2012] [Indexed: 06/01/2023]
Affiliation(s)
- M Salluzzo
- CNR-SPIN and Department of Physics, Complesso MonteSantangelo via Cinthia, I-80126 Napoli, Italy.
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25
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Achkar AJ, Sutarto R, Mao X, He F, Frano A, Blanco-Canosa S, Le Tacon M, Ghiringhelli G, Braicovich L, Minola M, Sala MM, Mazzoli C, Liang R, Bonn DA, Hardy WN, Keimer B, Sawatzky GA, Hawthorn DG. Distinct charge orders in the planes and chains of ortho-III-ordered YBa2Cu3O(6+δ) superconductors identified by resonant elastic x-ray scattering. Phys Rev Lett 2012; 109:167001. [PMID: 23215115 DOI: 10.1103/physrevlett.109.167001] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Indexed: 06/01/2023]
Abstract
Recently, charge density wave (CDW) order in the CuO(2) planes of underdoped YBa(2)Cu(3)O(6+δ) was detected using resonant soft x-ray scattering. An important question remains: is the chain layer responsible for this charge ordering? Here, we explore the energy and polarization dependence of the resonant scattering intensity in a detwinned sample of YBa(2)Cu(3)O(6.75) with ortho-III oxygen ordering in the chain layer. We show that the ortho-III CDW order in the chains is distinct from the CDW order in the planes. The ortho-III structure gives rise to a commensurate superlattice reflection at Q=[0.33 0 L] whose energy and polarization dependence agrees with expectations for oxygen ordering and a spatial modulation of the Cu valence in the chains. Incommensurate peaks at [0.30 0 L] and [0 0.30 L] from the CDW order in the planes are shown to be distinct in Q as well as their temperature, energy, and polarization dependence, and are thus unrelated to the structure of the chain layer. Moreover, the energy dependence of the CDW order in the planes is shown to result from a spatial modulation of energies of the Cu 2p to 3d(x(2)-y(2)) transition, similar to stripe-ordered 214 cuprates.
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Affiliation(s)
- A J Achkar
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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26
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Ghiringhelli G, Braicovich L, Schmitt T, Strocov V. High-resolution RIXS with the SAXES Spectrometer at the ADRESS Beamline of the Swiss Light Source. ACTA ACUST UNITED AC 2012. [DOI: 10.1080/08940886.2012.700843] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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27
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Ghiringhelli G, Le Tacon M, Minola M, Blanco-Canosa S, Mazzoli C, Brookes NB, De Luca GM, Frano A, Hawthorn DG, He F, Loew T, Moretti Sala M, Peets DC, Salluzzo M, Schierle E, Sutarto R, Sawatzky GA, Weschke E, Keimer B, Braicovich L. Long-Range Incommensurate Charge Fluctuations in (Y,Nd)Ba2Cu3O6+x. Science 2012; 337:821-5. [PMID: 22798406 DOI: 10.1126/science.1223532] [Citation(s) in RCA: 260] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- G Ghiringhelli
- CNR-SPIN, Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
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28
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Ilakovac V, Brookes NB, Cezar JC, Thakur P, Bisogni V, Dallera C, Ghiringhelli G, Braicovich L, Bernu S, Berger H, Forró L, Akrap A, Hague CF. BaVS3 probed by V L edge x-ray absorption spectroscopy. J Phys Condens Matter 2012; 24:045503. [PMID: 22217443 DOI: 10.1088/0953-8984/24/4/045503] [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] [Indexed: 05/31/2023]
Abstract
Polarization dependent vanadium L edge x-ray absorption spectra of BaVS(3) single crystals are measured in the four phases of the compound. The difference between signals with the polarizations E perpendicular to c and E is parallel to c (linear dichroism) changes with temperature. Besides increasing the intensity of one of the maxima, a new structure appears in the pre-edge region below the metal-insulator transition. More careful examination brings to light that the changes start already with pretransitional charge density wave fluctuations. Simple symmetry analysis suggests that the effect is related to rearrangements in the E(g) and A(1g) states, and is compatible with the formation of four inequivalent V-sites along the V-S chain.
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Affiliation(s)
- V Ilakovac
- Université Pierre et Marie Curie, CNRS UMR 7614, LCP-MR, Paris, France.
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29
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Guarise M, Dalla Piazza B, Moretti Sala M, Ghiringhelli G, Braicovich L, Berger H, Hancock JN, van der Marel D, Schmitt T, Strocov VN, Ament LJP, van den Brink J, Lin PH, Xu P, Rønnow HM, Grioni M. Measurement of magnetic excitations in the two-dimensional antiferromagnetic Sr₂CuO₂Cl₂ insulator using resonant x-ray scattering: evidence for extended interactions. Phys Rev Lett 2010; 105:157006. [PMID: 21230933 DOI: 10.1103/physrevlett.105.157006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Indexed: 05/30/2023]
Abstract
We measured the momentum dependence of magnetic excitations in the model spin-1/2 2D antiferromagnetic insulator Sr2CuO2Cl2 (SCOC). We identify a single-spin-wave feature and a multimagnon continuum, with different polarization dependences. The spin waves display a large (70 meV) dispersion between the zone-boundary points (π, 0) and (π/2, π/2). Employing an extended t-t'-t''-U one-band Hubbard model, we find significant electronic hopping beyond nearest-neighbor Cu ions, indicative of extended magnetic interactions. The spectral line shape at (π, 0) indicates sizable quantum effects in SCOC and probably more generally in the cuprates.
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Affiliation(s)
- M Guarise
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Switzerland
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30
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Braicovich L, van den Brink J, Bisogni V, Sala MM, Ament LJP, Brookes NB, De Luca GM, Salluzzo M, Schmitt T, Strocov VN, Ghiringhelli G. Magnetic excitations and phase separation in the underdoped La2-xSrxCuO4 superconductor measured by resonant inelastic X-ray scattering. Phys Rev Lett 2010; 104:077002. [PMID: 20366909 DOI: 10.1103/physrevlett.104.077002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Indexed: 05/23/2023]
Abstract
We probe the collective magnetic modes of La2CuO4 and underdoped La2-xSrxCuO4 (LSCO) by momentum resolved resonant inelastic x-ray scattering (RIXS) at the Cu L3 edge. For the undoped antiferromagnetic sample, we show that the single magnon dispersion measured with RIXS coincides with the one determined by inelastic neutron scattering, thus demonstrating that x rays are an alternative to neutrons in this field. In the spin dynamics of LSCO, we find a branch dispersing up to approximately 400 meV coexisting with one at lower energy. The high-energy branch has never been seen before. It indicates that underdoped LSCO is in a dynamic inhomogeneous spin state.
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Affiliation(s)
- L Braicovich
- CNR-INFM Coherentia and Soft, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
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31
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Ament LJP, Ghiringhelli G, Sala MM, Braicovich L, van den Brink J. Theoretical demonstration of how the dispersion of magnetic excitations in cuprate compounds can be determined using resonant inelastic X-ray scattering. Phys Rev Lett 2009; 103:117003. [PMID: 19792395 DOI: 10.1103/physrevlett.103.117003] [Citation(s) in RCA: 17] [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: 03/13/2009] [Indexed: 05/19/2023]
Abstract
We show that in resonant inelastic x-ray scattering (RIXS) at the copper L and M edge direct spin-flip scattering is in principle allowed. We demonstrate how this possibility can be exploited to probe the dispersion of magnetic excitations, for instance magnons, of cuprates such as the high T(c) superconductors. We compute the relevant local and momentum dependent magnetic scattering amplitudes, which we compare to the elastic and dd-excitation scattering intensities. For cuprates these theoretical results put RIXS as a technique on the same footing as neutron scattering.
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Affiliation(s)
- Luuk J P Ament
- Institute-Lorentz for Theoretical Physics, Universiteit Leiden, 2300 RA Leiden, The Netherlands
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32
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Ulrich C, Ament LJP, Ghiringhelli G, Braicovich L, Moretti Sala M, Pezzotta N, Schmitt T, Khaliullin G, van den Brink J, Roth H, Lorenz T, Keimer B. Momentum dependence of orbital excitations in Mott-insulating titanates. Phys Rev Lett 2009; 103:107205. [PMID: 19792341 DOI: 10.1103/physrevlett.103.107205] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Indexed: 05/28/2023]
Abstract
High-resolution resonant inelastic x-ray scattering has been used to determine the momentum dependence of orbital excitations in Mott-insulating LaTiO(3) and YTiO(3) over a wide range of the Brillouin zone. The data are compared to calculations in the framework of lattice-driven and superexchange-driven orbital ordering models. A superexchange model in which the experimentally observed modes are attributed to two-orbiton excitations yields the best description of the data.
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Affiliation(s)
- C Ulrich
- Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany
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33
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Schlappa J, Schmitt T, Vernay F, Strocov VN, Ilakovac V, Thielemann B, Rønnow HM, Vanishri S, Piazzalunga A, Wang X, Braicovich L, Ghiringhelli G, Marin C, Mesot J, Delley B, Patthey L. Collective magnetic excitations in the spin ladder Sr14Cu24O41 measured using high-resolution resonant inelastic x-ray scattering. Phys Rev Lett 2009; 103:047401. [PMID: 19659397 DOI: 10.1103/physrevlett.103.047401] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Indexed: 05/28/2023]
Abstract
We investigate magnetic excitations in the spin-ladder compound Sr_{14}Cu_{24}O_{41} using high-resolution Cu L_{3} edge resonant inelastic x-ray scattering (RIXS). Our findings demonstrate that RIXS couples to two-triplon collective excitations. In contrast to inelastic neutron scattering, the RIXS cross section changes only moderately over the entire Brillouin zone, revealing high sensitivity also at small momentum transfers, allowing determination of the two-triplon energy gap as 100 +/- 30 meV. Our results are backed by calculations within an effective Hubbard model for a finite-size cluster, and confirm that optical selection rules are obeyed for excitations from this spherically symmetric quantum spin-liquid ground state.
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Affiliation(s)
- J Schlappa
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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34
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Carpene E, Mancini E, Dallera C, Ghiringhelli G, Manzoni C, Cerullo G, De Silvestri S. A versatile apparatus for time-resolved photoemission spectroscopy via femtosecond pump-probe experiments. Rev Sci Instrum 2009; 80:055101. [PMID: 19485528 DOI: 10.1063/1.3125049] [Citation(s) in RCA: 7] [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] [Indexed: 05/27/2023]
Abstract
A laser-based system for time-resolved photoemission spectroscopy using up to 6.2 eV photons is presented. The versatility of the laser source permits several combinations of pump and probe photon energies with pulse durations of 50-100 fs. The ultrahigh vacuum system, equipped with evaporators, a low energy electron diffraction system and an Auger spectrometer, grants the possibility to grow and characterize thin films in situ. The electron energy analyzer is a time-of-flight spectrometer with a multianode detector allowing high count rates. The performance of the whole experimental setup is investigated on Cu(100), Cu(111), and Ag(111) single crystals.
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Affiliation(s)
- E Carpene
- Dipartimento di Fisica, CNR-INFM Ultras, Politecnico di Milano, p.zza Leonardo da Vinci 32, 20133 Milano, Italy.
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35
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Braicovich L, Ament LJP, Bisogni V, Forte F, Aruta C, Balestrino G, Brookes NB, De Luca GM, Medaglia PG, Granozio FM, Radovic M, Salluzzo M, van den Brink J, Ghiringhelli G. Dispersion of magnetic excitations in the cuprate La2CuO4 and CaCuO2 compounds measured using resonant x-ray scattering. Phys Rev Lett 2009; 102:167401. [PMID: 19518752 DOI: 10.1103/physrevlett.102.167401] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Indexed: 05/27/2023]
Abstract
By resonant inelastic x-ray scattering in the soft x-ray regime we probe the dynamical multiple-spin correlations in the antiferromagnetic cuprates La2CuO4 and CaCuO2. High resolution measurements at the copper L3 edge allow the clear observation of dispersing bimagnon excitations. Theory based on the ultrashort core-hole lifetime expansion fits the data on these coherent spin excitations without free parameters.
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Affiliation(s)
- L Braicovich
- CNR-INFM Coherentia and Soft, Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano, Italy
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36
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Salluzzo M, Cezar JC, Brookes NB, Bisogni V, De Luca GM, Richter C, Thiel S, Mannhart J, Huijben M, Brinkman A, Rijnders G, Ghiringhelli G. Orbital reconstruction and the two-dimensional electron gas at the LaAlO3/SrTiO3 interface. Phys Rev Lett 2009; 102:166804. [PMID: 19518739 DOI: 10.1103/physrevlett.102.166804] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Indexed: 05/27/2023]
Abstract
In 2004, Ohtomo and Hwang discovered that an electron gas is created at the interface between insulating LaAlO3 and SrTiO3 compounds. Here we show that the generation of a conducting electron gas is related to an orbital reconstruction occurring at the LaAlO3/SrTiO3 interface. Our results are based on extensive investigations of the electronic properties and of the orbital structure of the interface using x-ray absorption spectroscopy. In particular, we find that the degeneracy of the Ti 3d states is fully removed and that the Ti 3d xy levels become the first available states for conducting electrons.
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Affiliation(s)
- M Salluzzo
- CNR-INFM COHERENTIA, Complesso MonteSantangelo via Cinthia, 80126 Napoli, Italy.
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37
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Ghiringhelli G, Piazzalunga A, Dallera C, Schmitt T, Strocov VN, Schlappa J, Patthey L, Wang X, Berger H, Grioni M. Observation of two nondispersive magnetic excitations in NiO by resonant inelastic soft-X-Ray scattering. Phys Rev Lett 2009; 102:027401. [PMID: 19257316 DOI: 10.1103/physrevlett.102.027401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [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 present high resolution (DeltaE=120 meV) resonant inelastic x-ray scattering data measured at the Ni L3 edge (2p_{3/2}-->3d) on the paradigmatic antiferromagnetic oxide NiO. Spectra reveal clear signatures of magnetic excitations at approximately 95 and approximately 190 meV whose energy seems independent from transferred momentum. These spectral features are well reproduced by a single Ni2+ ion model in an effective exchange field. Within this local model the two magnetic excitations are characterized by a variation of the atomic magnetic moment along the local ordering direction (DeltaS_{alpha}) of one and two units. The DeltaS_{alpha}=2 case has different nature from bimagnons observed in optical Raman spectra, for which DeltaS_{alpha}=0.
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Affiliation(s)
- G Ghiringhelli
- CNR-INFM Coherentia and Soft, Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
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38
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Tebano A, Aruta C, Sanna S, Medaglia PG, Balestrino G, Sidorenko AA, De Renzi R, Ghiringhelli G, Braicovich L, Bisogni V, Brookes NB. Evidence of orbital reconstruction at interfaces in ultrathin La0.67Sr0.33MnO3 films. Phys Rev Lett 2008; 100:137401. [PMID: 18517994 DOI: 10.1103/physrevlett.100.137401] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Indexed: 05/26/2023]
Abstract
Linear dichroism (LD) in x-ray absorption, diffraction, transport, and magnetization measurements on thin La(0.7)Sr(0.3)MnO(3) films grown on different substrates, allow identification of a peculiar interface effect, related just to the presence of the interface. We report the LD signature of preferential 3d-e(g)(3z(2)-r(2)) occupation at the interface, suppressing the double exchange mechanism. This surface orbital reconstruction is opposite to that favored by residual strain and is independent of dipolar fields, the chemical nature of the substrate and the presence of capping layers.
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Affiliation(s)
- A Tebano
- CNR-INFM Coherentia and Dipartimento di Ingegneria Meccanica, Università di Roma Tor Vergata, Via del Politecnico 1, 00133 Roma, Italy
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39
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Moreschini L, Ghiringhelli G, Larsson K, Veit U, Brookes NB. A time-of-flight-Mott apparatus for soft x-ray spin resolved photoemission on solid samples. Rev Sci Instrum 2008; 79:033905. [PMID: 18377023 DOI: 10.1063/1.2868781] [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] [Indexed: 05/26/2023]
Abstract
We describe a new spectrometer for spin resolved photoemission from solids in the soft x-ray energy range. It is mounted on the ID08 beamline at the ESRF light source and consists of a time-of-flight (TOF) energy analyzer coupled to a retarding mini-Mott spin polarimeter. It represents a valid alternative to the spin detection system already available on ID08, especially for the acquisition of wide energy regions, where the TOF technique is extremely efficient. By testing the new spectrometer on the 4f levels of Au and on CuO at the Cu L3 threshold we show that the effective Sherman function and figure of merit achieved are, respectively, Seff approximately 0.16 and eta approximately 1.3x10(-4) and that for certain experiments we obtain a significant gain in intensity with respect to the previous system.
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Affiliation(s)
- L Moreschini
- European Synchrotron Radiation Facility (ESRF), Grenoble, BP 220, F38043 Grenoble Cedex, France
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40
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Salluzzo M, Ghiringhelli G, Cezar JC, Brookes NB, De Luca GM, Fracassi F, Vaglio R. Indirect electric field doping of the CuO2 planes of the cuprate NdBa2Cu3O7 superconductor. Phys Rev Lett 2008; 100:056810. [PMID: 18352415 DOI: 10.1103/physrevlett.100.056810] [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: 09/05/2007] [Indexed: 05/26/2023]
Abstract
The mechanism of field-effect doping in the 123 high critical temperature superconductors (HTS) has been investigated by x-ray absorption spectroscopy in the presence of an electric field. We demonstrate that holes are created at the CuO chains of the charge reservoir and that field-effect doping of the CuO(2) planes occurs by charge transfer, from the chains to the planes, of a fraction of the overall induced holes. The electronic properties of the charge reservoir and of the dielectric-HTS interface determine the electric field doping of the CuO(2) planes.
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Affiliation(s)
- M Salluzzo
- CNR-INFM COHERENTIA, Dipartimento di Scienze Fisiche Università di Napoli Federico II, Complesso di Monte S. Angelo, Via Cinthia, 80126 Napoli, Italy.
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41
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Kotani A, Matsubara M, Uozumi T, Ghiringhelli G, Fracassi F, Dallera C, Tagliaferri A, Brookes N, Braicovich L. Theoretical and experimental study of resonant inelastic X-ray scattering for NiO. Radiat Phys Chem Oxf Engl 1993 2006. [DOI: 10.1016/j.radphyschem.2005.07.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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42
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Braicovich L, Ghiringhelli G, Tagliaferri A, van der Laan G, Annese E, Brookes NB. Femtosecond dynamics in ferromagnetic metals investigated with soft x-ray resonant emission. Phys Rev Lett 2005; 95:267402. [PMID: 16486402 DOI: 10.1103/physrevlett.95.267402] [Citation(s) in RCA: 6] [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: 01/18/2005] [Indexed: 05/06/2023]
Abstract
We present measurements of the magnetic circular dichroism in x-ray resonant emission in the perpendicular geometry (circularly polarized x rays at normal incidence to the magnetization) for L(2,3) the absorption region in Fe, Co, and Ni metal. The results show that spin-dependent screening of the core hole takes place within the scattering time scale, which is supported by the absence of the effect in ionic systems. This allows an assessment of the time scale for the screening process (up to a few femtoseconds). The process is almost complete within the scattering time for Fe and Co, but this is not the case for the narrow band metal Ni which shows a much slower dynamics.
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Affiliation(s)
- L Braicovich
- INFM-CNR, Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, Milano, Italy
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43
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Chiuzbăian SG, Ghiringhelli G, Dallera C, Grioni M, Amann P, Wang X, Braicovich L, Patthey L. Localized electronic excitations in NiO studied with resonant inelastic X-Ray scattering at the Ni M threshold: evidence of spin flip. Phys Rev Lett 2005; 95:197402. [PMID: 16384022 DOI: 10.1103/physrevlett.95.197402] [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: 02/24/2005] [Indexed: 05/05/2023]
Abstract
We studied the neutral electronic excitations of NiO localized at the Ni sites by measuring the resonant inelastic x-ray scattering (RIXS) spectra at the Ni M2,3 edges. The good energy resolution allows an unambiguous identification of several spectral features due to excitations. The dependence of the RIXS spectra on the excitation energy gives evidence of local spin flip and yields a value of 125 +/- 15 meV for the antiferromagnetic exchange interaction. Accurate crystal field parameters are also obtained.
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Affiliation(s)
- S G Chiuzbăian
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
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44
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Minár J, Ebert H, De Nadaï C, Brookes NB, Venturini F, Ghiringhelli G, Chioncel L, Katsnelson MI, Lichtenstein AI. Experimental observation and theoretical description of the pure Fano effect in the valence-band photoemission of ferromagnets. Phys Rev Lett 2005; 95:166401. [PMID: 16241823 DOI: 10.1103/physrevlett.95.166401] [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: 05/23/2005] [Indexed: 05/05/2023]
Abstract
The pure Fano effect in angle-integrated valence-band photoemission of ferromagnets has been observed for the first time. A contribution of the intrinsic spin polarization to the spin polarization of the photoelectrons has been avoided by an appropriate choice of the experimental parameters. The theoretical description of the resulting spectra reveals a complete analogy to the Fano effect observed before for paramagnetic transition metals. While the theoretical photocurrent and spin-difference spectra are found in good quantitative agreement with experiment in the case of Fe and Co, only a qualitative agreement could be achieved in the case of Ni by calculations on the basis of plain local spin-density approximation. Agreement with experimental data could be improved in this case in a very substantial way by a treatment of correlation effects on the basis of dynamical mean field theory.
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Affiliation(s)
- J Minár
- Department Chemie, Physikalische Chemie, Universität München, Germany
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45
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Haverkort MW, Hu Z, Tanaka A, Ghiringhelli G, Roth H, Cwik M, Lorenz T, Schüssler-Langeheine C, Streltsov SV, Mylnikova AS, Anisimov VI, de Nadai C, Brookes NB, Hsieh HH, Lin HJ, Chen CT, Mizokawa T, Taguchi Y, Tokura Y, Khomskii DI, Tjeng LH. Determination of the orbital moment and crystal-field splitting in LaTiO3. Phys Rev Lett 2005; 94:056401. [PMID: 15783666 DOI: 10.1103/physrevlett.94.056401] [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: 04/23/2004] [Indexed: 05/24/2023]
Abstract
Utilizing a sum rule in a spin-resolved photoelectron spectroscopic experiment with circularly polarized light, we show that the orbital moment in LaTiO3 is strongly reduced from its ionic value, both below and above the Ne el temperature. Using Ti L2,3 x-ray absorption spectroscopy as a local probe, we found that the crystal-field splitting in the t2g subshell is about 0.12-0.30 eV. This large splitting does not facilitate the formation of an orbital liquid.
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Affiliation(s)
- M W Haverkort
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
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46
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Ghiringhelli G, Brookes NB, Annese E, Berger H, Dallera C, Grioni M, Perfetti L, Tagliaferri A, Braicovich L. Low energy electronic excitations in the layered cuprates studied by copper L3 resonant inelastic x-ray scattering. Phys Rev Lett 2004; 92:117406. [PMID: 15089169 DOI: 10.1103/physrevlett.92.117406] [Citation(s) in RCA: 18] [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: 08/07/2003] [Indexed: 05/24/2023]
Abstract
We have measured the resonant inelastic x-ray scattering (RIXS) spectra at the Cu L3 edge in a variety of cuprates. Exploiting a considerably improved energy resolution (0.8 eV) we recorded significant dependencies on the sample composition and orientation, on the scattering geometry, and on the incident photon polarization. The RIXS final states correspond to two families of electronic excitations, having local (dd excitations) and nonlocal (charge-transfer) character. The dd energy splitting can be estimated with a simple crystal field model. The RIXS at the L3 edge demonstrates here a great potential, thanks to the resonance strength and to the large 2p spin-orbit splitting.
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Affiliation(s)
- G Ghiringhelli
- INFM-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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47
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Steeneken PG, Tjeng LH, Sawatzky GA, Tanaka A, Tjernberg O, Ghiringhelli G, Brookes NB, Nugroho AA, Menovsky AA. Crossing the gap from p- to n-type doping: nature of the states near the chemical potential in La(2)-(x)Sr(x)CuO(4) and Nd(2-x)Ce(x)CuO(4-delta). Phys Rev Lett 2003; 90:247005. [PMID: 12857219 DOI: 10.1103/physrevlett.90.247005] [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: 02/02/2003] [Indexed: 05/24/2023]
Abstract
We report on an x-ray absorption and resonant photoemission study on single crystals of the high-T(c) cuprates La2-xSrxCuO4 and Nd(2-x)Ce(x)CuO(4-delta). Using an intrinsic energy reference, we find that the chemical potential of La2-xSrxCuO4 lies near the top of the La2CuO4 valence band whereas in Nd(2-x)Ce(x)CuO(4-delta) it is situated near the bottom of the Nd2CuO4 conduction band. The data clearly establish that the introduction of Ce in Nd2CuO4 results in electrons being doped into the CuO2 planes. We infer that the states closest to the chemical potential have a Cu 3d(10) singlet origin in Nd(2-x)Ce(x)CuO(4-delta) and a 3d(9)L singlet origin in La2-xSrxCuO4.
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Affiliation(s)
- P G Steeneken
- MSC, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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48
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Braicovich L, Tagliaferri A, van der Laan G, Ghiringhelli G, Brookes NB. Sum rules in x-ray resonant Raman scattering: recovering the Co ground state information in CoFe2O4 as a test case. Phys Rev Lett 2003; 90:117401. [PMID: 12688965 DOI: 10.1103/physrevlett.90.117401] [Citation(s) in RCA: 4] [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: 02/19/2002] [Indexed: 05/24/2023]
Abstract
We present an approach to x-ray resonant Raman scattering suitable for sum-rule analysis. In magnetic systems it gives ground state information as represented by an expansion in coupled multipoles of orbital and spin moments. The experiment is based on the angular dependence of the integrated peak intensities. In 3d transition elements one obtains information up to order 4 from the channel 2p(6)3d(n)-->2p(5)3d(n+1)-->2p(6)3s(1)3d(n+1). By combining these results with L(2,3) absorption dichroism, we show quantitatively the atomiclike properties of cobalt in CoFe2O4 up to high-order multipoles.
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Affiliation(s)
- L Braicovich
- INFM-Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milano, Italy
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49
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Steeneken PG, Tjeng LH, Elfimov I, Sawatzky GA, Ghiringhelli G, Brookes NB, Huang DJ. Exchange splitting and charge carrier spin polarization in EuO. Phys Rev Lett 2002; 88:047201. [PMID: 11801161 DOI: 10.1103/physrevlett.88.047201] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2001] [Indexed: 05/23/2023]
Abstract
High quality thin films of the ferromagnetic semiconductor EuO have been prepared and were studied using a new form of spin-resolved spectroscopy. We observed large changes in the electronic structure across the Curie and metal-insulator transition temperature. We found that these are caused by the exchange splitting of the conduction band in the ferromagnetic state, which is as large as 0.6 eV. We also present strong evidence that the bottom of the conduction band consists mainly of majority spins. This implies that doped charge carriers in EuO are practically fully spin polarized.
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Affiliation(s)
- P G Steeneken
- Solid State Physics Laboratory, Materials Science Centre, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Brookes NB, Ghiringhelli G, Tjernberg O, Tjeng LH, Mizokawa T, Li TW, Menovsky AA. Detection of Zhang-Rice singlets using spin-polarized photoemission. Phys Rev Lett 2001; 87:237003. [PMID: 11736472 DOI: 10.1103/physrevlett.87.237003] [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: 09/27/2000] [Indexed: 05/23/2023]
Abstract
From a spin-resolved photoemission study on the Bi(2)Sr(2)CaCu(2)O(8+delta) superconductor, we show experimentally that the first ionization state is of nearly pure singlet character. This is true both above and below the superconducting transition and in the presence of doping and band formation. This provides direct support for the existence and stability of Zhang-Rice singlets in high-temperature superconductors, justifying the ansatz of single-band models. Moreover, we establish this technique as an important probe for a wide range of cuprates and strongly correlated materials.
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Affiliation(s)
- N B Brookes
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble, France
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