1
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Li XT, Tu SJ, Chaix L, Fawaz C, d'Astuto M, Li X, Yakhou-Harris F, Kummer K, Brookes NB, Garcia-Fernandez M, Zhou KJ, Lin ZF, Yuan J, Jin K, Dean MPM, Liu X. Evolution of the Magnetic Excitations in Electron-Doped La_{2-x}Ce_{x}CuO_{4}. PHYSICAL REVIEW LETTERS 2024; 132:056002. [PMID: 38364146 DOI: 10.1103/physrevlett.132.056002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 12/12/2023] [Indexed: 02/18/2024]
Abstract
We investigated the high energy spin excitations in electron-doped La_{2-x}Ce_{x}CuO_{4}, a cuprate superconductor, by resonant inelastic x-ray scattering (RIXS) measurements. Efforts were paid to disentangle the paramagnon signal from non-spin-flip spectral weight mixing in the RIXS spectrum at Q_{∥}=(0.6π,0) and (0.9π,0) along the (1 0) direction. Our results show that, for doping level x from 0.07 to 0.185, the variation of the paramagnon excitation energy is marginal. We discuss the implication of our results in connection with the evolution of the electron correlation strength in this system.
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Affiliation(s)
- X T Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - S J Tu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - L Chaix
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - C Fawaz
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - M d'Astuto
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - X Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - F Yakhou-Harris
- European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex, France
| | - K Kummer
- European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex, France
| | - N B Brookes
- European Synchrotron Radiation Facility (ESRF), B.P. 220, F-38043 Grenoble Cedex, France
| | | | - Ke-Jin Zhou
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Z F Lin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J Yuan
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - K Jin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - M P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - X Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai 201210, China
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2
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Unconventional exciton evolution from the pseudogap to superconducting phases in cuprates. Nat Commun 2022; 13:7906. [PMID: 36550120 PMCID: PMC9780265 DOI: 10.1038/s41467-022-35210-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 11/18/2022] [Indexed: 12/24/2022] Open
Abstract
Electron quasiparticles play a crucial role in simplifying the description of many-body physics in solids with surprising success. Conventional Landau's Fermi-liquid and quasiparticle theories for high-temperature superconducting cuprates have, however, received skepticism from various angles. A path-breaking framework of electron fractionalization has been established to replace the Fermi-liquid theory for systems that show the fractional quantum Hall effect and the Mott insulating phenomena; whether it captures the essential physics of the pseudogap and superconducting phases of cuprates is still an open issue. Here, we show that excitonic excitation of optimally doped Bi2Sr2CaCu2O8+δ with energy far above the superconducting-gap energy scale, about 1 eV or even higher, is unusually enhanced by the onset of superconductivity. Our finding proves the involvement of such high-energy excitons in superconductivity. Therefore, the observed enhancement in the spectral weight of excitons imposes a crucial constraint on theories for the pseudogap and superconducting mechanisms. A simple two-component fermion model which embodies electron fractionalization in the pseudogap state provides a possible mechanism of this enhancement, pointing toward a novel route for understanding the electronic structure of superconducting cuprates.
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3
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Wan W, Christensen NB, Sandvik AW, Tregenna-Piggott P, Nilsen GJ, Mourigal M, Perring TG, Frost CD, McMorrow DF, Rønnow HM. Temperature dependence of the(π,0)anomaly in the excitation spectrum of the 2D quantum Heisenberg antiferromagnet. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:374007. [PMID: 32050188 DOI: 10.1088/1361-648x/ab757a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
It is well established that in the low-temperature limit, the two-dimensional quantum Heisenberg antiferromagnet on a square lattice (2DQHAFSL) exhibits an anomaly in its spectrum at short-wavelengths on the zone-boundary. In the vicinity of thepoint the pole in the one-magnon response exhibits a downward dispersion, is heavily damped and attenuated, giving way to an isotropic continuum of excitations extending to high energies. The origin of the anomaly and the presence of the continuum are of current theoretical interest, with suggestions focused around the idea that the latter evidences the existence of spinons in a two-dimensional system. Here we present the results of neutron inelastic scattering experiments and Quantum Monte Carlo calculations on the metallo-organic compound Cu(DCOO)D2O (CFTD), an excellent physical realisation of the 2DQHAFSL, designed to investigate how the anomaly atevolves up to finite temperatures. Our data reveal that on warming the anomaly survives the loss of long-range, three-dimensional order, and that it is thus a robust feature of the two-dimensional system. With further increase of temperature the zone-boundary response gradually softens and broadens, washing out theanomaly. This is confirmed by a comparison of our data with the results of finite-temperature Quantum Monte Carlo simulations where the two are found to be in good accord. In the vicinity of the antiferromagnetic zone centre, there was no significant softening of the magnetic excitations over the range of temperatures investigated.
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Affiliation(s)
- W Wan
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - N B Christensen
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - A W Sandvik
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, United States of America
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - P Tregenna-Piggott
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - G J Nilsen
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot OX11 0QX, United Kingdom
| | - M Mourigal
- School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30332, United States of America
| | - T G Perring
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot OX11 0QX, United Kingdom
| | - C D Frost
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot OX11 0QX, United Kingdom
| | - D F McMorrow
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - H M Rønnow
- Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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4
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Lai CY, Zhu JX. Ultrafast X-Ray Absorption Spectroscopy of Strongly Correlated Systems: Core Hole Effect. PHYSICAL REVIEW LETTERS 2019; 122:207401. [PMID: 31172773 DOI: 10.1103/physrevlett.122.207401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 04/25/2019] [Indexed: 06/09/2023]
Abstract
In recent years, ultrafast pump-probe spectroscopy has provided insightful information about the nonequilibrium dynamics of excitations in materials. In a typical experiment of time-resolved x-ray absorption spectroscopy, the systems are excited by a femtosecond laser pulse (pump pulse) followed by an x-ray probe pulse after a time delay to measure the absorption spectra of the photoexcited systems. We present a theory for nonequilibrium x-ray absorption spectroscopy in one-dimensional strongly correlated systems. The core hole created by the x ray is modeled as an additional effective potential of the core hole site, which changes the spectrum qualitatively. In equilibrium, the spectrum reveals the charge gap at half-filling and the metal-insulator transition in the presence of the core hole effect. Furthermore, a pump-probe scheme is introduced to drive the system out of equilibrium before the x-ray probe. The effects of the pump pulse with varying frequencies, shapes, and fluences are discussed for the dynamics of strongly correlated systems in and out of resonance. The spectrum indicates that the driven insulating state has a metallic droplet around the core hole. The rich structures of the nonequilibrium x-ray absorption spectrum give more insight into the dynamics of electronic structures.
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Affiliation(s)
- Chen-Yen Lai
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Jian-Xin Zhu
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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5
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Gu Q, Wan S, Tang Q, Du Z, Yang H, Wang QH, Zhong R, Wen J, Gu GD, Wen HH. Directly visualizing the sign change of d-wave superconducting gap in Bi 2Sr 2CaCu 2O 8+δ by phase-referenced quasiparticle interference. Nat Commun 2019; 10:1603. [PMID: 30962440 PMCID: PMC6453940 DOI: 10.1038/s41467-019-09340-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 03/07/2019] [Indexed: 11/29/2022] Open
Abstract
The superconducting state is formed by the condensation of Cooper pairs and protected by the superconducting gap. The pairing interaction between the two electrons of a Cooper pair determines the gap function. Thus, it is pivotal to detect the gap structure for understanding the mechanism of superconductivity. In cuprate superconductors, it has been well established that the gap may have a d-wave function. This gap function has an alternative sign change in the momentum space. It is however hard to visualize this sign change. Here we report the measurements of scanning tunneling spectroscopy in Bi2Sr2CaCu2O8+δ and conduct the analysis of phase-referenced quasiparticle interference (QPI). We see the seven basic scattering vectors that connect the octet ends of the banana-shaped contour of Fermi surface. The phase-referenced QPI clearly visualizes the sign change of the d-wave gap. Our results illustrate an effective way for determining the sign change of unconventional superconductors.
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Affiliation(s)
- Qiangqiang Gu
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Siyuan Wan
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Qingkun Tang
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Zengyi Du
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Huan Yang
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China.
| | - Qiang-Hua Wang
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China.
| | - Ruidan Zhong
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Jinsheng Wen
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - G D Gu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Hai-Hu Wen
- National Laboratory of Solid State Microstructures and Department of Physics, Center for Superconducting Physics and Materials, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, 210093, Nanjing, China.
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6
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Moretti Sala M, Martel K, Henriquet C, Al Zein A, Simonelli L, Sahle CJ, Gonzalez H, Lagier MC, Ponchut C, Huotari S, Verbeni R, Krisch M, Monaco G. A high-energy-resolution resonant inelastic X-ray scattering spectrometer at ID20 of the European Synchrotron Radiation Facility. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:580-591. [PMID: 29488940 DOI: 10.1107/s1600577518001200] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 01/19/2018] [Indexed: 06/08/2023]
Abstract
An end-station for resonant inelastic X-ray scattering and (resonant) X-ray emission spectroscopy at beamline ID20 of ESRF - The European Synchrotron is presented. The spectrometer hosts five crystal analysers in Rowland geometry for large solid angle collection and is mounted on a rotatable arm for scattering in both the horizontal and vertical planes. The spectrometer is optimized for high-energy-resolution applications, including partial fluorescence yield or high-energy-resolution fluorescence detected X-ray absorption spectroscopy and the study of elementary electronic excitations in solids. In addition, it can be used for non-resonant inelastic X-ray scattering measurements of valence electron excitations.
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Affiliation(s)
- M Moretti Sala
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - K Martel
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - C Henriquet
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - A Al Zein
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - L Simonelli
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - Ch J Sahle
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - H Gonzalez
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - M C Lagier
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - C Ponchut
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - S Huotari
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - R Verbeni
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - M Krisch
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - G Monaco
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38000 Grenoble, France
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7
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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. PHYSICAL REVIEW LETTERS 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] [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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8
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Dantz M, Pelliciari J, Samal D, Bisogni V, Huang Y, Olalde-Velasco P, Strocov VN, Koster G, Schmitt T. Quenched Magnon excitations by oxygen sublattice reconstruction in (SrCuO2)n/(SrTiO3)2 superlattices. Sci Rep 2016; 6:32896. [PMID: 27616448 PMCID: PMC5018731 DOI: 10.1038/srep32896] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/16/2016] [Indexed: 11/14/2022] Open
Abstract
The recently discovered structural reconstruction in the cuprate superlattice (SrCuO2)n/(SrTiO3)2 has been investigated across the critical value of n = 5 using resonant inelastic x-ray scattering (RIXS). We find that at the critical value of n, the cuprate layer remains largely in the bulk-like two-dimensional structure with a minority of Cu plaquettes being reconstructed. The partial reconstruction leads to quenching of the magnons starting at the Γ-point due to the minority plaquettes acting as scattering points. Although comparable in relative abundance, the doped charge impurities in electron-doped cuprate superconductors do not show this quenching of magnetic excitations.
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Affiliation(s)
- M. Dantz
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J. Pelliciari
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - D. Samal
- MESA+ Institute for Nanotechnology, University of Twente, Post Office Box 217, 7500AE Enschede, The Netherlands
| | - V. Bisogni
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Y. Huang
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - P. Olalde-Velasco
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - V. N. Strocov
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - G. Koster
- MESA+ Institute for Nanotechnology, University of Twente, Post Office Box 217, 7500AE Enschede, The Netherlands
| | - T. Schmitt
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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9
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Gretarsson H, Sung NH, Porras J, Bertinshaw J, Dietl C, Bruin JAN, Bangura AF, Kim YK, Dinnebier R, Kim J, Al-Zein A, Moretti Sala M, Krisch M, Le Tacon M, Keimer B, Kim BJ. Persistent Paramagnons Deep in the Metallic Phase of Sr_{2-x}La_{x}IrO_{4}. PHYSICAL REVIEW LETTERS 2016; 117:107001. [PMID: 27636488 DOI: 10.1103/physrevlett.117.107001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Indexed: 06/06/2023]
Abstract
We have studied the magnetic excitations of electron-doped Sr_{2-x}La_{x}IrO_{4} (0≤x≤0.10) using resonant inelastic x-ray scattering at the Ir L_{3} edge. The long-range magnetic order is rapidly lost with increasing x, but two-dimensional short-range order (SRO) and dispersive magnon excitations with nearly undiminished spectral weight persist well into the metallic part of the phase diagram. The magnons in the SRO phase are heavily damped and exhibit anisotropic softening. Their dispersions are well described by a pseudospin-1/2 Heisenberg model with exchange interactions whose spatial range increases with doping. We also find a doping-independent high-energy magnetic continuum, which is not described by this model. The spin-orbit excitons arising from the pseudospin-3/2 manifold of the Ir ions broaden substantially in the SRO phase, but remain largely separated from the low-energy magnons. Pseudospin-1/2 models are therefore a good starting point for the theoretical description of the low-energy magnetic dynamics of doped iridates.
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Affiliation(s)
- H Gretarsson
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - N H Sung
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - J Porras
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - J Bertinshaw
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - C Dietl
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - Jan A N Bruin
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - A F Bangura
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - Y K Kim
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 151-742, South Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
| | - R Dinnebier
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - Jungho Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Al-Zein
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France
| | - M Moretti Sala
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France
| | - M Krisch
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France
| | - M Le Tacon
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
- Karlsruher Institut für Technologie, Institut für Festkörperphysik, Hermann-v.-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
| | - B J Kim
- Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany
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10
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Huang HY, Jia CJ, Chen ZY, Wohlfeld K, Moritz B, Devereaux TP, Wu WB, Okamoto J, Lee WS, Hashimoto M, He Y, Shen ZX, Yoshida Y, Eisaki H, Mou CY, Chen CT, Huang DJ. Raman and fluorescence characteristics of resonant inelastic X-ray scattering from doped superconducting cuprates. Sci Rep 2016; 6:19657. [PMID: 26794437 PMCID: PMC4726252 DOI: 10.1038/srep19657] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 12/15/2015] [Indexed: 11/23/2022] Open
Abstract
Measurements of spin excitations are essential for an understanding of spin-mediated pairing for superconductivity; and resonant inelastic X-ray scattering (RIXS) provides a considerable opportunity to probe high-energy spin excitations. However, whether RIXS correctly measures the collective spin excitations of doped superconducting cuprates remains under debate. Here we demonstrate distinct Raman- and fluorescence-like RIXS excitations of Bi1.5Pb0.6Sr1.54CaCu2O8+δ. Combining photon-energy and momentum dependent RIXS measurements with theoretical calculations using exact diagonalization provides conclusive evidence that the Raman-like RIXS excitations correspond to collective spin excitations, which are magnons in the undoped Mott insulators and evolve into paramagnons in doped superconducting compounds. In contrast, the fluorescence-like shifts are due primarily to the continuum of particle-hole excitations in the charge channel. Our results show that under the proper experimental conditions RIXS indeed can be used to probe paramagnons in doped high-Tc cuprate superconductors.
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Affiliation(s)
- H Y Huang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.,Program of Science and Technology of Synchrotron Light Source, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - C J Jia
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Z Y Chen
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - K Wohlfeld
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, PL-02093 Warsaw, Poland
| | - B Moritz
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - T P Devereaux
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - W B Wu
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - J Okamoto
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - W S Lee
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Hashimoto
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Y He
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.,Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Z X Shen
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.,Department of Applied Physics, Stanford University, Stanford, California 94305, USA.,Department of Physics, Stanford University, Stanford, California 94305, USA
| | - Y Yoshida
- Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562, Japan
| | - H Eisaki
- Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562, Japan
| | - C Y Mou
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - C T Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - D J Huang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.,Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
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11
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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. PHYSICAL REVIEW LETTERS 2015; 114:217003. [PMID: 26066453 DOI: 10.1103/physrevlett.114.217003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [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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