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Jeudi 16/05/2019, à 14h00 Amphi Boreau escalier c, 2eme étage
Dynamical charge density fluctuations pervading the phase diagram of a Cu-based high-Tc superconductor
Resumé : Charge density modulations are a common occurrence in all families of high critical temperature superconducting cuprates. Although consistently observed 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 the temperature dependence of charge density modulations in YBa2Cu3O7-δ and Nd1+xBa2-xCu3O7-δ for several doping levels was carefully determined. It was found that short-range dynamical charge density fluctuations besides the previously known quasi-critical charge density waves persist up to well above the pseudogap temperature T*, are characterized by energies of few meV and pervade a large area of the phase diagram, so that they can play a key role in shaping the peculiar normal-state properties of cuprates.
Reference : R. Arpaia, S. Caprara, R. Fumagalli, G. De Vecchi, Y.Y. Peng, E. Andersson, D. Betto, G. M. De Luca, N. B. Brookes, F. Lombardi, M. Salluzzo, L. Braicovich1, C. Di Castro, M. Grilli, G. Ghiringhelli, to appear in Science (2019).
