From Magnons to the Resonance Peak: Spin Dynamics in High-TC Superconducting Cuprates by Inelastic Neutron Scattering

Bourgès, Philippe

doi:10.1007/0-306-47081-0_20

Cited by 9 publications

(6 citation statements)

References 76 publications

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“…In the case of BSCCO, this viewpoint is supported by STM measurements [43], which revealed that the conjectural boson feature does not depend on the oxygen stoichiometry δ, while the inhomogeneous gap distribution significantly shifts with δ. This is quite natural for crystal-lattice vibrations, whereas different magnetic excitation modes are strongly dependent on doping [188,189]. Moreover, the boson peak energy obtained in [43] is equal to 52 meV, which is different from the spin-resonance-mode energy of 43 meV inferred from neutron scattering data [189].…”

Section: The Problem Of Negative Conductancementioning

confidence: 69%

Temperature-dependent pseudogap-like features in tunnel spectra of high-T_ccuprates as a manifestation of charge-density waves

Ekino

Gabovich

et al. 2008

J. Phys.: Condens. Matter

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Temperature, T, variations of the tunnel conductance G(V) were calculated for junctions between a normal metal and a spatially inhomogeneous superconductor with a dielectric gap on the nested sections of the Fermi surface or between two such superconductors. The dielectric gapping was considered to be a consequence of the charge density wave (CDW) appearance due to the electron–phonon (for a Peierls insulator) or a Coulomb (for an excitonic insulator) interactions. Spatial averaging was carried out over random domains with varying parameters of the CDW superconductor (CDWS). The calculated tunnel spectra demonstrate a smooth transformation from asymmetric patterns with a pronounced dip–hump structure at low T into those with a pseudogap depletion of the electron densities of states at higher T in the vicinity or above the actual critical temperatures of the superconducting transition for any of the CDWS domains. Thus, it is demonstrated that both the dip-hump structure and pseudogapping are manifestations of the same phenomenon. A possible CDW-induced asymmetry of the background contribution to G(V) is also touched upon. The results explain the peculiar features of G(V) for Bi2Sr2CaCu2O8+δ and other related high-Tc cuprates.

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Section: The Problem Of Negative Conductancementioning

confidence: 69%

Temperature-dependent pseudogap-like features in tunnel spectra of high-T_ccuprates as a manifestation of charge-density waves

Ekino

Gabovich

et al. 2008

J. Phys.: Condens. Matter

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“…Accurate reflectance measurements in the infrared range and precise polarized neutron scattering data are available for a variety of oxides. [3][4][5] In this paper we show that conducting carriers studied by means of infrared spectroscopy reveal strong coupling to a resonance structure in the spectrum of spin fluctuations examined with neutron scattering. The coupling strength inferred from experiment is sufficient to account for high values of T c which signals the prominent role of spin excitations in the superconductivity of oxides.There have been many suggestions as to the mechanism involved in the superconductivity of the oxides.…”

mentioning

confidence: 75%

“…2, we see that the coupling to the 41 meV resonance is larger in the experiment than the value assumed in the calculations that generated the theoretical results of that frame. This is not surprising since we have used the spin polarized inelastic neutron scattering data set measured on a near optimum 91 K sample of YBa 2 Cu 3 O 6.92 while the neutron results for slightly overdoped YBCO are very different 5 although the T c value is hardly affected. This large dependence of χ(ω) on the sample can be used to argue against their role in establishing T c .…”

mentioning

confidence: 99%

Coupling strength of charge carriers to spin fluctuations in high-temperature superconductors

Ćarbotte

Schachinger

Basov

1999

Nature

223

277

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In conventional superconductors, the most direct evidence of the mechanism responsible for superconductivity comes from tunnelling experiments, which provide a clear picture of the underlying electron-phonon interactions. As the coherence length in conventional superconductors is large, the tunnelling process probes several atomic layers into the bulk of the material; the observed structure in the current-voltage characteristics at the phonon energies gives, through inversion of the Eliashberg equations, the electron-phonon spectral density alpha2F(omega). The situation is different for the high-temperature copper oxide superconductors, where the coherence length (particularly for c-axis tunnelling) can be very short. Because of this, methods such as optical spectroscopy and neutron scattering provide a better route for investigating the underlying mechanism, as they probe bulk properties. Accurate reflection measurements at infrared wavelengths and precise polarized neutron-scattering data are now available for a variety of the copper oxides, and here we show that the conducting carriers (probed by infrared spectroscopy) are strongly coupled to a resonance structure in the spectrum of spin fluctuations (measured by neutron scattering). The coupling strength inferred from those results is sufficient to account for the high transition temperatures of the copper oxides, highlighting a prominent role for spin fluctuations in driving superconductivity in these materials.

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“…Celles-ci sont mises en évidence par diffusion inélastique des neutrons, qui comme nous l'avons vu dans le cours de F. Moussa, donne une information directe sur la dépendance en énergie de la partie imaginaire de la susceptibilité magnétique, Im (Q AF , ). La Figure 4 présente les mesures neutrons de Im (Q AF , ) dans l'état normal pour différentes valeurs de dopages en trous dans le cuprate YBa 2 Cu 3 O 6+x [5]. Dans le régime sous-dopé, Im (Q AF , ) présente un pic intense, large en énergie et asymétrique, dont la position du maximum d'intensité se situe autour de 15 meV dans l'échantillon le plus sous-dopé et se déplace à plus haute énergie en augmentant le dopage.…”

Section: Un éTat Microscopique Complexe Et Encore Incompris Dans Le Runclassified

“…. ) évoluent comme le facteur de forme magnétique des orbitales d x 2 −y 2 de l'ion Cu 2+ [5,65]. Ce facteur est anisotrope dans le plan de base et son intensité diminue à mesure que l'amplitude du vecteur d'onde transféré augmente.…”

Section: La Section De Diffusion Inélastique Magnétique Dans Les Cuprunclassified

Utilisation de la diffusion des neutrons dans l’étude des mécanismes microscopiques à l’origine de la supraconductivité

Pailhés

2010

JDN 16 – Diffusion Inélastique Des Neutrons Pour l'Etude Des Excitations Dans La Matiére Condensée

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Résumé. La supraconductivité non conventionnelle est certainement l'un des phénomènes les plus remarquables associés à la physique des systèmes dits à fortes corrélations électroniques. Dans ces systèmes, les degrés de liberté du spin et de la charge de l'électron sont très fortement couplés, de sorte que le déplacement des charges est contraint par l'environnement magnétique formé par leurs spins. La diffusion inélastique des neutrons est l'unique sonde expérimentale permettant de photographier l'état magnétique de ces systèmes dans tout l'espace réciproque et de suivre son évolution sur une échelle d'énergie parfaitement adaptée à celle de la supraconductivité. A travers l'exemple des cuprates supraconducteurs à haute température critique, nous montrons comment la diffusion inélastique des neutrons apporte des informations uniques permettant de comprendre l'organisation électronique de ces systémes à l'échelle microscopique et les mécanismes mise en jeu dans l'apparition de la supraconductivté.

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From Magnons to the Resonance Peak: Spin Dynamics in High-TC Superconducting Cuprates by Inelastic Neutron Scattering

Cited by 9 publications

References 76 publications

Temperature-dependent pseudogap-like features in tunnel spectra of high-T_ccuprates as a manifestation of charge-density waves

Temperature-dependent pseudogap-like features in tunnel spectra of high-T_ccuprates as a manifestation of charge-density waves

Coupling strength of charge carriers to spin fluctuations in high-temperature superconductors

Utilisation de la diffusion des neutrons dans l’étude des mécanismes microscopiques à l’origine de la supraconductivité

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From Magnons to the Resonance Peak: Spin Dynamics in High-TC Superconducting Cuprates by Inelastic Neutron Scattering

Cited by 9 publications

References 76 publications

Temperature-dependent pseudogap-like features in tunnel spectra of high-Tccuprates as a manifestation of charge-density waves

Temperature-dependent pseudogap-like features in tunnel spectra of high-Tccuprates as a manifestation of charge-density waves

Coupling strength of charge carriers to spin fluctuations in high-temperature superconductors

Utilisation de la diffusion des neutrons dans l’étude des mécanismes microscopiques à l’origine de la supraconductivité

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Product

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Temperature-dependent pseudogap-like features in tunnel spectra of high-T_ccuprates as a manifestation of charge-density waves

Temperature-dependent pseudogap-like features in tunnel spectra of high-T_ccuprates as a manifestation of charge-density waves