Hot Spots and Transition from d-Wave to Another Pairing Symmetry in the Electron-Doped Cuprate Superconductors

TL;DR

This paper offers a simple theoretical explanation for the transition from d-wave to another pairing symmetry, likely triplet p-wave, in electron-doped cuprate superconductors as doping increases.

Contribution

It proposes a mechanism where hot spots' movement suppresses d-wave pairing, leading to a transition to s-wave or triplet p-wave pairing, with a focus on triplet pairing.

Findings

D-wave pairing is suppressed as hot spots approach Brillouin zone diagonals.

Transition to s-wave or triplet p-wave pairing occurs with increased doping.

Triplet p-wave pairing is favored and discussed for experimental verification.

Abstract

We present a simple theoretical explanation for a transition from d-wave to another superconducting pairing observed in the electron-doped cuprates. The d_{x^2-y^2} pairing potential Delta, which has the maximal magnitude and opposite signs at the hot spots on the Fermi surface, becomes suppressed with the increase of electron doping, because the hot spots approach the Brillouin zone diagonals, where Delta vanishes. Then, the d_{x^2-y^2} pairing is replaced by either singlet s-wave or triplet p-wave pairing. We argue in favor of the latter and discuss experiments to uncover it.