Proposed experiment: out-of-plane nodal lines in Sr${}_2$RuO${}_4$

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.