Physics – Condensed Matter – Superconductivity
Scientific paper
2010-07-20
Physical Review B 82, 064513 (2010)
Physics
Condensed Matter
Superconductivity
29 Pages, 21 Figures, Submitted to PRB
Scientific paper
10.1103/PhysRevB.82.064513
The large variations of T$_c$ across the cuprate families is one of the major unsolved puzzles in condensed matter physics, and is poorly understood. Although there appears to be a great deal of universality in the cuprates, several orders of magnitude changes in T$_c$ can be achieved through changes in the chemical composition and structure of the unit cell. In this paper we formulate a systematic examination of the variations in electron-phonon coupling to oxygen phonons in the cuprates, incorporating a number of effects arising from several aspects of chemical composition and doping across cuprate families. It is argued that the electron-phonon coupling is a very sensitive probe of the material-dependent variations of chemical structure, affecting the orbital character of the band crossing the Fermi level, the strength of local electric fields arising from structural-induced symmetry breaking, doping dependent changes in the underlying band structure, and ionicity of the crystal governing the ability of the material to screen $c$-axis perturbations. Using electrostatic Ewald calculations and known experimental structural data, we establish a connection between the material's maximal T$_c$ at optimal doping and the strength of coupling to $c$-axis modes. We demonstrate that materials with the largest coupling to the out-of-phase bond-buckling (``$B_{1g}$") oxygen phonon branch also have the largest T$_c$'s. In light of this observation we present model T$_c$ calculations using a two-well model where phonons work in conjunction with a dominant pairing interaction, presumably due to spin fluctuations, indicating how phonons can generate sizeable enhancements to T$_c$ despite the relatively small coupling strengths. Combined, these results can provide a natural framework for understanding the doping and material dependence of T$_c$ across the cuprates.
Devereaux Thomas P.
Johnston Scott
Moritz Brian
Nagaosa Naoto
Shen Zhi-Xun
No associations
LandOfFree
A Systematic Study of Electron-Phonon Coupling to Oxygen Modes Across the Cuprates does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Systematic Study of Electron-Phonon Coupling to Oxygen Modes Across the Cuprates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Systematic Study of Electron-Phonon Coupling to Oxygen Modes Across the Cuprates will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-126098