Single origin of the nodal and antinodal gaps in cuprates

¹ Sorbonne Université, Institut des Nanosciences de Paris, CNRS, UMR 7588 - 4 Place Jussieu, 75005 Paris, France
² Sorbonne Université, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, UMR 7590 4 Place Jussieu, 75005 Paris, France

^(a) yves.noat@insp.jussieu.fr (corresponding author)

Received: 20 February 2019
Accepted: 17 June 2019

Abstract

Recent angle-resolved photoemission electron spectroscopy (ARPES) experiments demonstrate that the momentum dependence of the spectral gap in underdoped cuprates does not follow a pure d-wave form (Anzai H. et al., Nat. Commun., 4 (2013) 1815). This deviation is highly controversial. It has often been interpretated as a proof of the non-superconducting origin of the antinodal gap in the underdoped regime. In this paper, we show that the measured angular dependence of the spectral gap can be explained by the basic nature of pairs in high-T_c cuprates. Hole pairs, or pairons, form as a result of the local antiferromagnetic environment on the scale , the magnetic coherence length. The spatial extension of the pairon wave function beyond first nearest neighbours gives rise to the anomalous angular dependence of the gap, in quantitative agreement with experiments. This simple interpretation strongly indicates the common origin of the nodal and antinodal gaps.