Proposed experiment: out-of-plane nodal lines in Sr$_{2}$RuO$_{4}$

TL;DR

This paper proposes a tunneling spectroscopy experiment to investigate the existence of out-of-plane nodal lines in Sr$_{2}$RuO$_{4}$, a superconductor with unconventional chiral order, aiming to clarify its gap structure.

Contribution

It introduces a novel experimental approach to detect out-of-plane nodal lines in Sr$_{2}$RuO$_{4}$, addressing unresolved questions about its superconducting gap topology.

Findings

Potential identification of out-of-plane nodal lines.

Enhanced understanding of Sr$_{2}$RuO$_{4}$'s gap structure.

Guidance for future experimental investigations.

Abstract

Since the original proposal of an unconventional chiral order parameter in the ruthenate perovskite superconductor Sr$_{2}$RuO$_{4}$, much attention has been given to the possibility of out-of-plane nodal lines on the predominant $\gamma$ cylindrical Fermi surface given evidence for low-lying quasiparticle excitations in this material. Here I propose a tunneling spectroscopy experiment to determine whether such nodal lines in fact exist.