Spin-glass state in nickelate superconductors

Abstract

Magneto-optical measurements in La0.8Sr0.2NiO2 and Nd0.825Sr0.175NiO2 reveal an intriguing new facet of infinite-layer nickelate superconductors: the onset of spin-glass behavior at a temperature far exceeding the superconducting critical temperature Tc. This discovery sharply contrasts with copper oxide superconductors, where magnetism and superconductivity remain largely exclusive. Moreover, the magnitude and onset temperature of the polar Kerr effect in Nd0.825Sr0.175NiO2 fabricated on SrTiO3 and (LaAlO3)0.3(Sr2TaAlO6)0.7 substrates differ dramatically, while Tc does not.