Muon spin rotation studies of magnetism in superconducting infinite layer nickelates*

The recent discovery and ongoing expansion of a new family of superconductors, the hole-doped infinite layer rare earth nickelates (La,Pr,Nd)_1-xSr_xNiO₂ ^1–4, has provoked much research activity with the goal of understanding their fundamental nature as well as their similarities to cuprates. One of the central questions has been their magnetic state with no long-range order observed in the bulk parent compounds ⁵ but magnetic excitations detected on the nickel sites ⁶.

 

Muon spin rotation offers a unique opportunity to probe intrinsic magnetism with extremely local sensitivity. With superconductivity so far only observed in thin film samples, low energy muons with a minimum implantation depth of just a few nanometers are utilized. Muon decay asymmetry spectra were recorded for various members of the superconducting infinite layer nickelate family. The effect of the rare earth ion and hole-doping through strontium substitution have been investigated.