In materials science, much effort has been devoted to reproduce superconductivity in chemical compositions analogous to cuprate superconductors since their discovery over thirty years ago. This approach was recently successful in realising superconductivity in infinite-layer nickelates. Although differing from cuprates in electronic and magnetic properties, strong Coulomb interactions suggest infinite-layer nickelates have a propensity to various symmetry-breaking orders that populate the cuprates. Here we report the observation of charge density waves (CDWs) in infinite-layer NdNiO2 films using Ni-L3 resonant x-ray scattering. Remarkably, CDWs form in Nd 5d and Ni 3d orbitals at the same commensurate wavevector (0.333,0)r.l.u., with non-negligible out-of-plane dependence, and an in-plane correlation length up to ∼ 60 Angstrom. Spectroscopic studies reveal a strong connection between CDWs and the Nd 5d - Ni 3d orbital hybridisation. Upon entering the superconducting state at 20\% Sr doping, the CDWs disappear. Our work demonstrates the existence of CDWs in infinite-layer nickelates with a multi-orbital character distinct from cuprates, which establishes their low-energy physics.
@article{arxiv.2112.04440,
title = {Charge density waves in infinite-layer NdNiO$_2$ nickelates},
author = {Charles C. Tam and Jaewon Choi and Xiang Ding and Stefano Agrestini and Abhishek Nag and Bing Huang and Huiqian Luo and Mirian García-Fernández and Liang Qiao and Ke-Jin Zhou},
journal= {arXiv preprint arXiv:2112.04440},
year = {2022}
}