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Start Over Author "d'Astuto, Matteo" Topic condensed matter::superconductivity
12 results on '"d'Astuto, Matteo"'

1. Phonon anomalies with doping in superconducting oxychlorides Ca2-xCuO2Cl2

Author

Lebert, Blair W., Yamamoto, Hajime, Azuma, Masaki, Heid, Rolf, Tsutsui, Satoshi, Uchiyama, Hiroshi, Baron, Alfred Q. R., Baptiste, Benoît, and d'Astuto, Matteo

Subjects
Superconductivity (cond-mat.supr-con), Condensed Matter - Strongly Correlated Electrons, Strongly Correlated Electrons (cond-mat.str-el), Condensed Matter - Superconductivity, Condensed Matter::Superconductivity, FOS: Physical sciences, Condensed Matter::Strongly Correlated Electrons
Abstract

We measure the dispersion of the Cu-O bond-stretching phonon mode in the high-temperature superconducting parent compound Ca$_2$CuO$_2$Cl$_2$. Our density functional theory calculations predict a cosine-shaped bending of the dispersion along both the ($\xi$00) and ($\xi\xi$0) directions, while comparison with previous results on Ca$_{1.84}$CuO$_2$Cl$_2$ show it only along ($\xi$00), suggesting an anisotropic effect which is not reproduced in calculation at optimal doping. Comparison with isostructural La$_{2-x}$Sr$_x$CuO$_4$ suggests that these calculations reproduce well the overdoped regime, however they overestimate the doping effect on the Cu-O bond-stretching mode at optimal doping.

Published
2019
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2. Observation of low energy dispersive modes in un- derdoped (La, Nd) 2−x Sr x CuO 4

Author

'Astuto, Matteo D, Denis, Sylvain, Graf, Jeff, Lanzara, Alessandra, Decorse, Claudia, Giura, Paola, Cheong, Sang-Wook, Shukla, Abhay, Berthet, Patrick, Lamago, Daniel, Castellan, John-Paul, Bossak, Alexei, Krisch, Michael, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Materials Science Division [LBNL Berkeley], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Department of Physics, Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Institut fur Festkorperphysik, European Synchrotron Radiation Facility (ESRF), ESRF experiment HS-2440 and HS-2689 and LLB through experiment N. 11234. U.S. Department of Energy under Contract No. DE-AC03-76SF00098. Berkeley Labs programs on 'Quantum Materials' funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Material. National Science Foundation through Grant No. DMR-0349361 and DMR-0405682. University of California, Berkeley, through (France Berkeley Fund Grant)., and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
74.72.Gh74.72.Kf74.25.Kc63.20.kd63.20.dd78.70.Ck78.70.Nx, Strongly Correlated Electrons (cond-mat.str-el), Properties of superconductors: phonons, Condensed Matter - Superconductivity, Pseudogap regime in cuprate superconductors, Phonons in crystal lattices, FOS: Physical sciences, Phonon-electron interactions, Hole-doped cuprate superconductors, X-ray scattering, Superconductivity (cond-mat.supr-con), [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Condensed Matter - Strongly Correlated Electrons, Neutron inelastic scattering, Condensed Matter::Superconductivity, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Abstract

We find excitations lower in energy than known phonon modes in underdoped La$\_{2-x}$Sr$\_x$CuO$\_{4+\delta}$ (x=0.08), with both inelastic X-Ray scattering (IXS) and inelastic neutron scattering (INS). A non dispersive excitation at 9 meV is identified and is also seen by INS in (La,Nd)$\_{2-x}$Sr$\_x$CuO$\_{4+\delta}$, with 40$\%$ Nd substitution. INS also identifies a still lower energy dispersive mode at low q in the Nd free sample. These modes are clearly distinct from the longitudinal acoustic phonon and correspond in energy to the Zone Centre modes measured by optical spectroscopy and associated with stripe dynamics.

Published
2015

3. Non-adiabatic effects in the phonon dispersion of Mg 1--x Al x B 2

Author

d'Astuto, Matteo, Heid, Rolf, Renker, Burkhard, Weber, Frank, Schober, Helmut, Omar, de La Pena Seaman, Karpinski, Janusz, Zhigadlo, Nikolai D., Bossak, Alexei, Krisch, Michael, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Institut für Festkörperphysik, Institut Laue-Langevin (ILL), ILL, Instituto de Física [Puebla] (IFUAP BUAP), Benemérita Universidad Autónoma de Puebla (BUAP), Laboratory for Solid State Physics (ETH Zurich), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Chemistry and Biochemistry, Université de Bernes, and European Synchrotron Radiation Facility (ESRF)

Subjects
[PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Superconductivity (cond-mat.supr-con), Condensed Matter - Superconductivity, Superconducting binary compounds, Condensed Matter::Superconductivity, Phonons in superconductors, Density functional theory, Phonon-electron interactions, FOS: Physical sciences, Condensed Matter::Strongly Correlated Electrons, X-ray scattering, 74.70.Ad, 74.25.Kc, 63.20.kd, 78.70.Ck, 71.15.Mb
Abstract

published online 25 May 2016, in the 1 May 2016 issue of Physical Review B Rapid (Vol.93, No.18):http://link.aps.org/doi/10.1103/PhysRevB.93.180508; Superconducting MgB$_2$ shows an E$_{2g}$ zone center phonon, as measured by Raman spectroscopy, that is very broad in energy and temperature dependent. The Raman shift and lifetime show large differences with the values elsewhere in the Brillouin Zone measured by Inelastic X-ray Scattering (IXS), where its dispersion can be accounted for by standard harmonic phonon theory, adding only a moderate electron-phonon coupling. Here we show that the effects rapidly disappear when electron-phonon coupling is switched off by Al substitution on the Mg sites. Moreover, using IXS with very high wave-vector resolution in MgB$_2$, we can follow the dispersion connecting the Raman and the IXS signal, in agreement with a theory using only electron-phonon coupling but without strong anharmonic terms. The observation is important in order to understand the effects of electron-phonon coupling on zone center phonons modes in MgB$_2$, but also in all metals characterized by a small Fermi velocity in a particular direction, typical for layered compounds.

Published
2015
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4. Phonon anomalies and lattice dynamics in superconducting oxychlorides Ca$_{2-x}$CuO$_2$Cl

Author

D'Astuto, Matteo, Yamada, Ikuya, Giura, Paola, Paulatto, Lorenzo, Gauzzi, Andrea, Hoesch, Moritz, Krisch, Michael, Azuma, Masaki, and Takano, Mikio

Subjects
Superconductivity (cond-mat.supr-con), Condensed Matter - Strongly Correlated Electrons, Strongly Correlated Electrons (cond-mat.str-el), Condensed Matter - Superconductivity, Condensed Matter::Superconductivity, FOS: Physical sciences, Condensed Matter::Strongly Correlated Electrons
Abstract

We present a comprehensive study of the phonon dispersion in an underdoped, superconducting Ca$_{2-x}$CuO$_2$Cl$_2$ crystal. We interpret the results using lattice dynamical calculations based on a shell model, and we compare the results, to other hole-doped cuprates, in particular to the ones isomorphic to La$_{2-x}$Sr$_x$CuO$_4$ (LSCO). We found that an anomalous dip in the Cu-O bond stretching dispersion develops in oxychlorides with a simultaneous marked broadening of the mode. The broadening is maximum at $\approx (\pi / (2a) ~ 0 ~ 0)$ that corresponds to the charge-modulations propagation vector. Our analysis also suggests that screening effects in calculations may cause an apparent cosine-shaped bending of the Cu-O bond-stretching dispersion along both the ($q$ 0 0) and ($q$ $q$ 0) directions, that is not observed on the data close to optimal doping. This observation suggests that the discrepancy between experimental data and \textit{ab-initio} calculations on this mode originates from an overestimation of the doping effects on the mode.

Published
2013
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5. Sharp optical phonon softening close to optimal doping in La$_{2-x}$Ba$_x$CuO$_{4+\delta}$

Author

D'Astuto, Matteo, Dhalenne, Guy, Graf, Jeff, Hoesch, Moritz, Giura, Paola, Krisch, Michael, Berthet, Patrick, Lanzara, Alessandra, Shukla, Abhay, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physico-Chimie de l'Etat Solide (CHIMSOL), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Materials Science Division [LBNL Berkeley], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), European Synchrotron Radiation Facility (ESRF), Department of Physics [Berkeley], University of California [Berkeley], University of California-University of California, Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley] (UC Berkeley), and University of California (UC)-University of California (UC)

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter::Superconductivity, 74.25.Kc, 74.72.Dn, 63.20.Dj, 63.20.Kr, 78.70.Ck, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Abstract

International audience; We report a direct observation of a sharp Kohn-like anomaly in the doubly degenerate copper-oxygen bond-stretching phonon mode occurring at $\mathbf{q}\mathrm{=(0.3, 0,0)}$ in La$_{2-x}$Ba$_x$CuO$_{4+\delta}$ with $\mathrm{x=0.14\pm0.01}$, thanks to the high $\mathbf{Q}$ resolution of inelastic x-ray scattering. This anomaly is clearly seen when the inelastic signal is analysed using a single mode but is also consistent with a two mode hypothesis possibly due to a splitting of the degenerate modes due to symmetry breaking stripes. Our observation shows that the effect persists at the stripe propagation vector in a superconducting system close to optimal doping.

Published
2008
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6. Bond stretching phonon softening and kinks in the angle-resolved photoemission spectra of optimally doped Bi2Sr1.6La0.4Cu2O6+delta superconductors

Author

Graf, Jeff, D'Astuto, Matteo, Jozwiak, C., Garcia, D.R., Saini, Naurang L., Krisch, Michael, Ikeuchi, K., Baron, A Q.R., Eisaki, H., Lanzara, Alessandra, Materials Science Division [LBNL Berkeley], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Berkeley], University of California [Berkeley], University of California-University of California, Dipartimento di Fisica, Università di Roma La Sapienza, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], European Synchrotron Radiation Facility (ESRF), RIKEN SPring-8 Center [Hyogo] (RIKEN RSC), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), National Institute of Advanced Industrial Science and Technology (AIST), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA)

Subjects
Condensed Matter::Materials Science, DISPERSION, LATTICE-DYNAMICS, Condensed Matter::Superconductivity, 74.72.Hs, 74.25.Jb, 74.25.Kc, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Abstract

International audience; 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=(approximate to 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 >= 0.22, corresponding exactly to the soft part of the bond stretching phonon.

Published
2008

7. Sharp optical phonon softening close to optimal doping in La$_{2-x}$Ba$_x$CuO$_{4+��}$

Author

D'Astuto, Matteo, Dhalenne, Guy, Graf, Jeff, Hoesch, Moritz, Giura, Paola, Krisch, Michael, Berthet, Patrick, Lanzara, Alessandra, and Shukla, Abhay

Subjects
Strongly Correlated Electrons (cond-mat.str-el), Condensed Matter::Superconductivity, FOS: Physical sciences
Abstract

We report a direct observation of a sharp Kohn-like anomaly in the doubly degenerate copper-oxygen bond-stretching phonon mode occurring at $\mathbf{q}\mathrm{=(0.3, 0,0)}$ in La$_{2-x}$Ba$_x$CuO$_{4+��}$ with $\mathrm{x=0.14\pm0.01}$, thanks to the high $\mathbf{Q}$ resolution of inelastic x-ray scattering. This anomaly is clearly seen when the inelastic signal is analysed using a single mode but is also consistent with a two mode hypothesis possibly due to a splitting of the degenerate modes due to symmetry breaking stripes. Our observation shows that the effect persists at the stripe propagation vector in a superconducting system close to optimal doping.

Published
2008
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8. In-plane copper-oxygen bond-stretching mode anomaly in underdoped La2−xSrxCuO4+delta measured with high-resolution inelastic x-ray scattering

Author

Graf, Jeff, d'Astuto, Matteo, Giura, Paola, Shukla, Abhay, Saini, Naurang L., Bossak, Alexei, Krisch, Michael, Cheong, Sang-Wook, Sasagawa, Takao, Lanzara, Alessandra, Materials Science Division [LBNL Berkeley], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Fisica, Università di Roma La Sapienza, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], European Synchrotron Radiation Facility (ESRF), Rutgers Center for Emergent Materials and Department of Physics & Astronomy, Rutgers, Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo (UTokyo), Department of Physics [Berkeley], University of California [Berkeley], University of California-University of California, Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), University of California [Berkeley] (UC Berkeley), and University of California (UC)-University of California (UC)

Subjects
[PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Condensed Matter::Superconductivity, 74.72.Dn, 63.20.Kr, 63.20.Dj, 74.25.Kc, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Abstract

International audience; We have measured the lattice dynamics of underdoped La2-xSrxCuO4+ x=0.08 using high resolution inelastic x-ray scattering spectroscopy. The very good intrinsic Q resolution of this experiment allows us to differentiate between the two proposed scenarios for the Cu-O bond stretching phonon broadening reported at q=0.25,0,0. The results suggest that this phonon broadening is due to intrinsic damping rather than to a steep dispersion, having important implications on the interpretation of phonon anomalies in cuprates.

Published
2007
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9. Anharmonic effects in MgB2? A comparative inelastic X-ray scattering and Raman study

Author

D'Astuto, Matteo, Calandra, Matteo, Reich, Stephanie, Shukla, Abhay, Lazzeri, Michele, Mauri, Francesco, Karpinski, Janusz, Zhigadlo, N.D., Bossak, Alexei, Krisch, Michael, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Laboratory for Solid State Physics, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), European Synchrotron Radiation Facility (ESRF), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Materials Science and Engineering, Massachusetts Institute of Technology, Laboratory for Solid State Physics [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)

Subjects
Condensed Matter - Materials Science, ab initio calculations, Condensed Matter - Superconductivity, phonon spectra, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, type II superconductors, X-ray scattering, magnesium compounds, Superconductivity (cond-mat.supr-con), [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Condensed Matter::Superconductivity, anharmonic lattice modes, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Raman spectra, Physics::Atomic Physics, PACS: 74.70.Ad, 74.25.Kc, 63.20.Dj, 63.20.Kr
Abstract

We study anharmonic effects in MgB2 by comparing Inelastic X-ray and Ramanscattering together with ab-initio calculations. Using high statistics and high q resolution measurements we show that the E2g mode linewidth is independent of temperature along Gamma-A. We show, contrary to previous claims, that the Raman-peak energy decreases as a function of increasing temperature, a behaviour inconsistent with all the anharmonic ab-initio calculations of the E2g mode at Gamma available in literature. These findings and the excellent agreement between the X-ray measured and ab-initio calculated phonon spectra suggest that anharmonicity is not the main mechanism determining the temperature behaviour of the Raman-peak energy. The Raman E2g peak position and linewidth can be explained by large dynamical effects in the phonon self-energy. In light of the present findings, the commonly accepted explanation of the reduced isotope effect in terms of anharmonic effects needs to be reconsidered., Comment: 11 pages, 10 figures

Published
2007
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10. Low-q dispersion of transverse acoustic phonons in YBa$_2$Cu$_3$O$_{7-\delta}$

Author

Gauzzi, Andrea, D'Astuto, Matteo, Licci, Francesca, Bossak, Alexei, Krisch, Michael, Istituto dei Materiali per l'Elettronica ed il Magnetismo [Genova] (IMEM-CNR), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Physique de la Matière Condensée (PMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Consiglio Nazionale delle Ricerche (CNR), and Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
[PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity, Condensed Matter::Superconductivity, 74.72.Bk, 74.25.Kc, 78.70.Ck, phonons, X-ray scattering, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], Y-based cuprates
Abstract

International audience; High-resolution ($\Delta E$=1.3 meV) inelastic X-ray scattering (IXS) in optimally doped untwinned YBa$_2$Cu$_3$O$_{7-\delta}$ single crystals show that the dispersion of transverse acoustic phonons in the a-direction remains linear with no softening due to bending modes in the long wavelength limit, down to q=0.02. The sound velocity is found to be 2700 +/- 70 m s$^{-1}$, in excellent agreement with ultrasound measurements, and unchanged upon cooling from room temperature to 98 K. These results rule out a strong coupling between bending dynamics of the CuO$_2$ planes and charge carriers in cuprates.

Published
2007
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11. In-plane copper-oxygen bond-stretching mode anomaly in underdoped La2−xSrxCuO4+ measured with high-resolution inelastic x-ray scattering

Author

Graf, Jeff, D'Astuto, Matteo, Giura, Paola, Shukla, Abhay, L. Saini, Naurang, Bossak, Alexei, Krisch, Michael, Cheong, Sang-Wook, Sasagawa, Takao, Lanzara, Alessandra, Materials Science Division [LBNL Berkeley], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Fisica, Università di Roma La Sapienza, Dipartimento di Fisica, European Synchrotron Radiation Facility (ESRF), Rutgers Center for Emergent Materials and Department of Physics & Astronomy, Okayama University, Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, and The University of Tokyo (UTokyo)

Subjects
[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Condensed Matter::Superconductivity, PACS : 74.72.Dn, 63.20.Kr, 63.20.Dj, 74.25.Kc, Condensed Matter::Strongly Correlated Electrons
Abstract

International audience; We have measured the lattice dynamics of underdoped La2-xSrxCuO4+ x=0.08 using high resolution inelastic x-ray scattering spectroscopy. The very good intrinsic Q resolution of this experiment allows us to differentiate between the two proposed scenarios for the Cu-O bond stretching phonon broadening reported at q=0.25,0,0. The results suggest that this phonon broadening is due to intrinsic damping rather than to a steep dispersion, having important implications on the interpretation of phonon anomalies in cuprates.

Published
2007
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12. Low-q dispersion of transverse acoustic phonons in YBa$_2$Cu$_3$O$_{7-��}$

Author

Gauzzi, Andrea, D'Astuto, Matteo, Licci, Francesca, Bossak, Alexei, and Krisch, Michael

Subjects
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el), Condensed Matter::Superconductivity, FOS: Physical sciences
Abstract

High-resolution ($��E$=1.3 meV) inelastic X-ray scattering (IXS) in optimally doped untwinned YBa$_2$Cu$_3$O$_{7-��}$ single crystals show that the dispersion of transverse acoustic phonons in the a-direction remains linear with no softening due to bending modes in the long wavelength limit, down to q=0.02. The sound velocity is found to be 2700 +/- 70 m s$^{-1}$, in excellent agreement with ultrasound measurements, and unchanged upon cooling from room temperature to 98 K. These results rule out a strong coupling between bending dynamics of the CuO$_2$ planes and charge carriers in cuprates.

Published
2004
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