← Back to search

Effect of nonmagnetic impurities on the gap of a dx2−y2 superconductor as seen by angle-resolved photoemission

R. Fehrenbacher

DOI 10.1103/PhysRevB.54.6632 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

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 nonmagnetic impurity scattering in the presence of a dx2−y2 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. Nonmagnetic impurities further amplify this effect by introducing additional spectral weight around zero frequency. At sufficiently large impurity concentrations ni≈0.02−0.05, this results in an extended region of gaplessness up to δφ=±7 (φ 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.

Source-reported materials — not catalogue approval

FormulaReported Tc (K)Pressure (GPa)Type
Bi2Sr2CaCu2O8

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

—Pressure not reportedunknown

Similar papers