The discovery of superconductivity in a d9−δ nickelate has inspired disparate theoretical perspectives regarding the essential physics of this class of materials. A key issue is the magnitude of the magnetic superexchange, which relates to whether cuprate-like high-temperature nickelate superconductivity could be realized. We address this question using Ni L-edge and O K-edge spectroscopy of the reduced trilayer nickelate d9−1/3 La4Ni3O8 and associated theoretical modeling. A magnon energy scale of ~80 meV resulting from a nearest-neighbor magnetic exchange of J=69(4)4 meV is observed, proving that d9−δ nickelates can host a large superexchange. This value, along with that of the Ni-O hybridization estimated from our O K-edge data, implies that trilayer nickelates represent an intermediate case between the infinite-layer nickelates and the cuprates, and suggests that they represent a promising route towards higher-temperature nickelate superconductivity.
@article{arxiv.2008.08209,
title = {Strong Superexchange in a $d^{9-{\delta}}$ Nickelate Revealed by Resonant Inelastic X-Ray Scattering},
author = {J. Q. Lin and P. Villar Arribi and G. Fabbris and A. S. Botana and D. Meyers and H. Miao and Y. Shen and D. G. Mazzone and J. Feng and S. G. Chiuzbaian and A. Nag and A. C. Walters and M. Garcia-Fernandez and Ke-Jin Zhou and J. Pelliciari and I. Jarrige and J. W. Freeland and Junjie Zhang and J. F. Mitchell and V. Bisogni and X. Liu and M. R. Norman and M. P. M. Dean},
journal= {arXiv preprint arXiv:2008.08209},
year = {2021}
}
Comments
7 pages not including supplmentary material; To appear in Physical Review Letters