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arXiv · 2008.08209

Strong Superexchange in a $d^{9-{\delta}}$ Nickelate Revealed by Resonant Inelastic X-Ray Scattering

J. Q. Lin·P. Villar Arribi·G. Fabbris·A. S. Botana·D. Meyers·H. Miao·Y. Shen·D. G. Mazzone·J. Feng·S. G. Chiuzbaian·A. Nag·A. C. Walters·M. Garcia-Fernandez·Ke-Jin Zhou·J. Pelliciari·I. Jarrige·J. W. Freeland·Junjie Zhang·J. F. Mitchell·V. Bisogni·X. Liu·M. R. Norman·M. P. M. Dean
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Abstract

The discovery of superconductivity in a $d^{9-{\delta}}$ 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 $d^{9-1/3}$ 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 $d^{9-{\delta}}$ 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.

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J. Q. Lin, P. Villar Arribi, G. Fabbris, A. S. Botana, D. Meyers, H. Miao, Y. Shen, D. G. Mazzone, J. Feng, S. G. Chiuzbaian, A. Nag, A. C. Walters, M. Garcia-Fernandez, Ke-Jin Zhou, J. Pelliciari, I. Jarrige, J. W. Freeland, Junjie Zhang, J. F. Mitchell, V. Bisogni, X. Liu, M. R. Norman, M. P. M. Dean. 2020-08-19. Strong Superexchange in a $d^{9-{\delta}}$ Nickelate Revealed by Resonant Inelastic X-Ray Scattering. https://doi.org/10.1103/physrevlett.126.087001

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