In search for the pairing glue in cuprates by non-equilibrium optical spectroscopy

10th International Conference on Materials and Mechanisms of Superconductivity

Cilento, F.^1 ; Conte, S Dal^2,3 ; Coslovich, G.^4 ; Banfi, F.^2,3 ; Ferrini, G.^2,3 ; Eisaki, H.^5 ; Greven, M.^6 ; Damascelli, A.^7,8 ; Marel, D Van Der^9 ; Parmigiani, F.^1,10 ; Giannetti, C.^2,3

Sincrotrone Trieste S.C.p.A., Basovizza I-34012, Italy^1

I-LAMP (Interdisciplinary Laboratories for Advanced Materials Physics), Università Cattolica Del Sacro Cuore, Brescia I-25121, Italy^2

Department of Mathematics and Physics, Università Cattolica Del Sacro Cuore, Brescia I-25121, Italy^3

Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States^4

Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8568 Tsukuba, Japan^5

School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States^6

Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada^7

Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada^8

Département de Physique de la Matière Condensée, Université de Genève, Genève CH1211, Switzerland

(10) Department of Physics, Università Degli Studi di Trieste, Trieste I-34127, Italy^9

关键词: Electronic and optical properties;    Fermionic quasiparticles;    High critical temperature;    Strongly correlated materials;    Superconducting phase transitions;    Ultra-fast spectroscopies;    Ultra-short light pulse;    Unconventional superconductors;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/449/1/012003/pdf
DOI  :  10.1088/1742-6596/449/1/012003

来源: IOP

【 摘 要 】

In strongly correlated materials the electronic and optical properties are significantly affected by the coupling of fermionic quasiparticles to different degrees of freedom, such as lattice vibrations and bosonic excitations of electronic origin. Broadband ultrafast spectroscopy [1, 2] is emerging as the premier technique to unravel the subtle interplay between quasiparticles and electronic or phononic collective excitations, by their different characteristic timescales and spectral responses. By investigating the femtosecond dynamics of the optical properties of Bi2Sr2Ca0.92Y0.08Cu2O8+δ (Y-Bi2212) crystals over the 0.5-2 eV energy range, we disentangle the electronic and phononic contributions to the generalized electron-boson Eliashberg function [3, 4], showing that the spectral distribution of the electronic excitations, such as spin fluctuations and current loops, and the strength of their interaction with quasiparticles can account for the high critical temperature of the superconducting phase transition [5]. Finally, we discuss how the use of this technique can be extended to the underdoped region of the phase diagram of cuprates, in which a pseudogap in the quasiparticle density of states opens. The microscopic modeling of the interaction of ultrashort light pulses with unconventional superconductors will be one of the key challenges of the next-years materials science, eventually leading to the full understanding of the role of the electronic correlations in controlling the dynamics on the femtosecond timescale.