Effect of non-magnetic impurities on the gap of a $d_{x^2-y^2}$ superconductor as seen by angle-resolved photoemission

Дата и время публикации : 1996-03-15T18:58:43Z

Авторы публикации и институты :
Roland Fehrenbacher (Max-Planck-Institut, Stuttgart, Germany)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 8 pages uuencoded gzipped Postscript
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: An analysis of angle-resolved photoemission (ARPES) experiments in the superconducting state of the high tc copper-oxides is presented. It is based on a phenomenological weak-coupling BCS model which incorporates the experimental normal state dispersion extracted from ARPES, and non-magnetic impurity scattering in the presence of a $d_{x^2-y^2}$ order parameter (OP). It is shown, that already in the pure case, the broadening by finite momentum resolution of the analyzer leads to a finite region of apparent `gaplessness’ around the true node of the OP. Non-magnetic impurities further amplify this effect by introducing additional spectral weight around zero frequency. At sufficiently large impurity concentrations $n_iapprox 0.02-0.05$, this results in an extended region of `gaplessness’ up to $deltaphi=pm7$ ($phi$ the angle on the Fermi surface) around the true node for a large range of moderate to strong impurity potential strengths. Different ways to identify the presence of impurity scattering in the ARPES spectra are proposed.

Category: Physics