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arXiv · 2011.05029

Paramagnons and high-temperature superconductivity in mercury-based cuprates

Lichen Wang·Guanhong He·Zichen Yang·Mirian Garcia-Fernandez·Abhishek Nag·Ke-Jin Zhou·Matteo Minola·Matthieu Le Tacon·Bernhard Keimer·Yingying Peng·Yuan Li
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Abstract

We present a comparative study of magnetic excitations in the first two Ruddlesden-Popper members of the Hg-family of high-temperature superconducting cuprates, which are chemically nearly identical and have the highest critical temperature ($T_\mathrm{c}$) among all cuprate families. Our inelastic photon scattering experiments reveal that the two compounds' paramagnon spectra are nearly identical apart from an energy scale factor of $\sim130\%$ that matches the ratio of $T_\mathrm{c}$'s, as expected in magnetic Cooper pairing theories. By relating our observations to other cuprates, we infer that the strength of magnetic interactions determines how high $T_\mathrm{c}$ can reach. Our finding can be viewed as a magnetic analogue of the isotope effect, thus firmly supporting models of magnetically mediated high-temperature superconductivity.

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Lichen Wang, Guanhong He, Zichen Yang, Mirian Garcia-Fernandez, Abhishek Nag, Ke-Jin Zhou, Matteo Minola, Matthieu Le Tacon, Bernhard Keimer, Yingying Peng, Yuan Li. 2020-11-10. Paramagnons and high-temperature superconductivity in mercury-based cuprates. https://doi.org/10.1038/s41467-022-30918-z

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