Nature of the Nodal Kink in Angle-Resolved Photoemission Spectra of Cuprate Superconductors

Abstract

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 upon 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 $\lambda$ allows a unified description of the nodal-kink effect. Our study reveals that distinction between $\lambda$ and the technically defined mass-enhancement parameter ${\lambda }^{\ast }$ 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).

Accepted to PRB Vol. 79 Issue 5 (Feb-2009). 20 pages, 4 figures. ARPES, Kink, Electron-Phonon coupling, Mass-enhancement parameter

References in corpus (4)

• Laser ARPES, the sudden approximation, and quasiparticle-like peaks in Bi2Sr2CaCu2O8+delta
• Self-consistent self-energy analysis of photoemission data
• Bare electron dispersion from photoemission experiments
• Momentum dependence of the electron-phonon coupling and self-energy effects in YBa_2Cu_3O_7 within the local density approximation

Cited by in corpus (5)

• Continuous Decoupling of Dynamically Expanding Systems
• Phonon origin of low energy and high energy kinks in high temperature cuprate superconductors
• Colossal band renormalization and stoner ferromagnetism induced by electron-antiferromagnetic-magnon coupling
• Large momentum-dependence of the main dispersion "kink" in the high-Tc superconductor Bi2Sr2CaCu2O8+δ
• Anomalous doping evolution of nodal dispersion revealed by in-situ ARPES on continuously doped cuprates