Absence of 3a0 charge density wave order in the infinite-layer nickelate NdNiO2
C. T. Parzyck, Naman Gupta, Y. Wu, V. Anil, Lopa Bhatt, M. Bouliane, Rantong Gong, Benjamin Gregory, Aileen Luo, Ronny Sutarto, Feizhou He, Yi‐De Chuang, Tao Zhou, G. Herranz, Lena F. Kourkoutis, Andrej Singer, Darrell G. Schlom, D. G. Hawthorn, Kyle Shen
Abstract
Abstract A hallmark of many unconventional superconductors is the presence of many-body interactions that give rise to broken-symmetry states intertwined with superconductivity. Recent resonant soft X-ray scattering experiments report commensurate 3 a 0 charge density wave order in infinite-layer nickelates, which has important implications regarding the universal interplay between charge order and superconductivity in both cuprates and nickelates. Here we present X-ray scattering and spectroscopy measurements on a series of NdNiO 2+ x samples, which reveal that the signatures of charge density wave order are absent in fully reduced, single-phase NdNiO 2 . The 3 a 0 superlattice peak instead originates from a partially reduced impurity phase where excess apical oxygens form ordered rows with three-unit-cell periodicity. The absence of any observable charge density wave order in NdNiO 2 highlights a crucial difference between the phase diagrams of cuprate and nickelate superconductors.