HIGHLIGHTS OF 2020

# The dawn of the nickel age of superconductivity

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An Author Correction to this article was published on 25 November 2020

Whereas high-temperature superconductivity in cuprates has been studied for 30 years, during the past year it has been reported in nickelates. This raises new questions for physicists and chemists about the mechanism of superconductivity — despite the electronic similarities of Cu and Ni, it seems that nickelate superconductivity requires consideration of a second orbital.

• Extraction of layers of oxygen ions from thin films of perovskite structure (Nd,Sr)NiO2 has led to emergence of the long sought nickelate superconductivity.

• Comparison of the nickelate with the isostructural and isovalent, high temperature superconducting, cuprate has framed the main debate on the importance of their obvious similarities and less evident differences.

• Several observations — electronic, magnetic, and structural — point toward a new frontier Ni $${d}_{{z}^{2}}$$ orbital, with its role in interlayer coupling, in addition to the $${d}_{{x}^{2}-{y}^{2}}$$ orbital that has dominated the discussion in cuprate superconductivity.

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## Change history

• ### 25 November 2020

An Erratum to this paper has been published:https://doi.org/10.1038/s42254-020-00265-3.

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## Acknowledgements

The author acknowledges collaboration with K.-W. Lee, and several exchanges with A. S. Botana. This work was supported by National Science Foundation Grant DMR 1607139. For the computations we used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1548562.

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Correspondence to Warren E. Pickett.

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Pickett, W.E. The dawn of the nickel age of superconductivity. Nat Rev Phys (2020). https://doi.org/10.1038/s42254-020-00257-3