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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}. Phys Rev Lett 2024; 132:056002. [PMID: 38364146 DOI: 10.1103/physrevlett.132.056002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [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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Monza A, Meffre A, Baudelet F, Rueff JP, d'Astuto M, Munsch P, Huotari S, Lachaize S, Chaudret B, Shukla A. Iron under pressure: "Kohn tweezers" and remnant magnetism. Phys Rev Lett 2011; 106:247201. [PMID: 21770592 DOI: 10.1103/physrevlett.106.247201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Indexed: 05/31/2023]
Abstract
In this work we investigate the magnetic and structural properties of bulk Fe and Fe nanoparticles under pressure with x-ray absorption and emission spectroscopies providing answers to two fundamental questions: (a) the chicken-or-egg problem for the magnetic and structural transitions and (b) magnetism in the high pressure hcp phase. The two transitions, inextricably linked in the bulk, are clearly decoupled in the nanoparticles, with the magnetic collapse preceding the structural transition. Ultrafast x-ray emission spectroscopy detects remnant magnetism, probably antiferromagnetic fluctuations, up to pressures of about 40 GPa in the hcp phase. This could be of direct relevance to the superconductivity in ϵ-Fe [K. Shimizu et al., Nature (London) 412, 316 (2001)] through the existence of a quantum critical point and associated magnetic fluctuations.
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Affiliation(s)
- A Monza
- Université Pierre et Marie Curie, IMPMC, CNRS UMR7590, Paris, France
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Graf J, d'Astuto M, Jozwiak C, Garcia DR, Saini NL, Krisch M, Ikeuchi K, Baron AQR, Eisaki H, Lanzara A. Bond stretching phonon softening and kinks in the angle-resolved photoemission spectra of optimally doped Bi2Sr1.6La0.4Cu2O6+delta superconductors. Phys Rev Lett 2008; 100:227002. [PMID: 18643447 DOI: 10.1103/physrevlett.100.227002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Indexed: 05/26/2023]
Abstract
We report the first measurement of the Cu-O bond stretching phonon dispersion in optimally doped Bi2Sr1.6La0.4Cu2O6+delta using inelastic x-ray scattering. We found a softening of this phonon at q=( approximately 0.25,0,0) from 76 to 60 meV, similar to the one reported in other cuprates. A comparison with angle-resolved photoemission data on the same sample revealed an excellent agreement in terms of energy and momentum between the angle-resolved photoemission nodal kink and the soft part of the bond stretching phonon. Indeed, we find that the momentum space where a 63+/-5 meV kink is observed can be connected with a vector q=(xi,0,0) with xi > or =0.22, corresponding exactly to the soft part of the bond stretching phonon.
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Affiliation(s)
- J Graf
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Emery N, Hérold C, d'Astuto M, Garcia V, Bellin C, Marêché JF, Lagrange P, Loupias G. Superconductivity of bulk CaC6. Phys Rev Lett 2005; 95:087003. [PMID: 16196893 DOI: 10.1103/physrevlett.95.087003] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Indexed: 05/04/2023]
Abstract
We have obtained bulk samples of the graphite intercalation compound, CaC6, by a novel method of synthesis from highly oriented pyrolytic graphite. The crystal structure has been completely determined showing that it is the only member of the MC6, metal-graphite compounds that has rhombohedral symmetry. We have clearly shown the occurrence of superconductivity in the bulk sample at 11.5 K, using magnetization measurements.
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Affiliation(s)
- N Emery
- Laboratoire de Chimie du Solide Minéral-UMR 7555, Université Henri Poincaré Nancy I, B.P. 239, 54506 Vandoeuvre-lès-Nancy Cedex, France
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Mathon O, Baudelet F, Itié JP, Polian A, d'Astuto M, Chervin JC, Pascarelli S. Dynamics of the magnetic and structural alpha-epsilon phase transition in iron. Phys Rev Lett 2004; 93:255503. [PMID: 15697906 DOI: 10.1103/physrevlett.93.255503] [Citation(s) in RCA: 15] [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: 05/18/2004] [Indexed: 05/24/2023]
Abstract
We have studied the high-pressure iron bcc to hcp phase transition by simultaneous x-ray magnetic circular dichroism and x-ray absorption spectroscopy with an x-ray energy dispersive spectrometer. The combination of the two techniques allows us to obtain simultaneously information on both the structure and the magnetic state of iron under pressure. The magnetic and structural transitions simultaneously observed are sharp. Both are of first order in agreement with the theoretical prediction. The pressure domain of the transition observed (2.4+/-0.2 GPa) is narrower than that usually cited in the literature (8 GPa). Our data indicate that the magnetic transition slightly precedes the structural one, suggesting that the origin of the instability of the bcc phase in iron with increasing pressure is to be attributed to the effect of pressure on magnetism as predicted by spin-polarized full-potential total energy calculations.
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Affiliation(s)
- O Mathon
- European Synchrotron Radiation Facility, BP 220, 38043 Grenoble CEDEX, France
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d'Astuto M, Mang PK, Giura P, Shukla A, Ghigna P, Mirone A, Braden M, Greven M, Krisch M, Sette F. Anomalous dispersion of longitudinal optical phonons in Nd(1.86)Ce(0.14)CuO(4+delta) determined by inelastic x-ray scattering. Phys Rev Lett 2002; 88:167002. [PMID: 11955249 DOI: 10.1103/physrevlett.88.167002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2001] [Indexed: 05/23/2023]
Abstract
The phonon dispersions of Nd(1.86)Ce(0.14)CuO(4+delta) along the [xi,0,0] direction have been determined by inelastic x-ray scattering. Compared to the undoped parent compound, the two highest longitudinal phonon branches, associated with the Cu-O bond stretching and out-of-plane oxygen vibration, are shifted to lower energies. Moreover, an anomalous softening of the bond-stretching band is observed at about q = (0.2,0,0). These signatures provide evidence for strong electron-phonon coupling in this electron-doped high-temperature superconductor.
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Affiliation(s)
- M d'Astuto
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France
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