2008/11/30 by H. S. Ruiz, Antonio Badía-Majós, A. Badía
Physics and Astronomy · #Advanced Chemical Physics Studies #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.79.054528
published as Phys. Rev. B 79, 054528 (2009) · Accepted to PRB Vol. 79 Issue 5 (Feb-2009). 20 pages, 4 figures. ARPES, Kink, Electron-Phonon coupling, Mass-enhancement parameter
arxiv created 2009/02/13 · openalex publication_date 2009/02/27 · arxiv updated 2010/05/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The experimental finding of an ubiquitous kink in the nodal direction of angle-resolved photoemission spectroscopies of superconducting cuprates has been reproduced theoretically. Our model is built on the Migdal-Eliashberg theory for the electron self-energy within the phonon-coupling scenario. Following this perturbative approach, a numerical evaluation of the bare band dispersion energy in terms of the electron-phonon-coupling parameter \ensuremathλ allows a unified description of the nodal-kink effect. Our study reveals that distinction between \ensuremathλ and the technically defined mass-enhancement parameter \ensuremathλ^\ensuremath∗ is relevant for the quantitative description of data, as well as for a meaningful interpretation of previous studies. A remarkable agreement between theory and experiment has been achieved for different samples and at different doping levels. The full energy spectrum is covered in the case of LSCO, Bi2212, and overdoped Y123. In the case of underdoped Y123, the model applies to the low-energy region (close to Fermi level).