2009/06/01 by E. Schachinger, J. P. Carbotte, J. P. Ćarbotte +1
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #High-pressure geophysics and materials #Iron-based superconductors research #Physics of Superconductivity and Magnetism #cond-mat.supr-con
paper · pdf · doi:10.1209/0295-5075/86/67003
published as Europhys. Lett. 86, 67003 (2009) · 6 pages, 3 figures
openalex publication_date 2009/06/01 · arxiv created 2009/06/15 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
There is an ongoing debate about the nature of the bosonic excitations responsible for the quasiparticle self-energy in high-temperature superconductors —are they phonons or spin fluctuations? We present a careful analysis of the bosonic excitations as revealed by the "kink" feature at 70 meV in angle-resolved photoemission data using Eliashberg theory for a d -wave superconductor. Starting from the assumption that nodal quasiparticles are not coupled to the (π, π) magnetic resonance, the sharp structure at 70 meV can be assigned to phonons. We find that not only can we account for the shifts of the kink energy seen on oxygen isotope substitution but also get a quantitative estimate of the fraction of the area under the electron-boson spectral density which is due to phonons. We conclude that for optimally doped Bi 2 Sr 2 CaCu 2 O 8+δ phonons contribute ∼10% and non-phononic excitations ∼90%.