Disorder-induced suppression of superconductivity in infinite-layer nickelates

TL;DR

This study investigates how disorder affects superconductivity in infinite-layer nickelates, revealing that increasing defects suppress superconductivity and indicating an unconventional pairing mechanism with a sign-changing order parameter.

Contribution

It introduces a novel experimental approach using electron irradiation to probe the pairing symmetry in nickelate superconductors.

Findings

Superconductivity is completely suppressed by disorder.

Results suggest an unconventional, sign-changing order parameter.

Disorder acts as a pair-breaker in these materials.

Abstract

The pairing symmetry of superconducting infinite-layer nickelates is a fundamental yet experimentally challenging question. We employ high-energy electron irradiation to induce disorder in superconducting Nd$_{0.825}$Sr$_{0.175}$NiO$_2$ thin films and examine the impact of pair-breaking defects on superconductivity and elucidate the nature of the superconducting gap. Our measurements reveal a complete suppression of superconductivity with increasing disorder, suggesting an unconventional, sign-changing order parameter.