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Direct relation between the low-energy spin excitations and superconductivity of overdoped high-$T_c$ superconductors

S. Wakimoto·H. Zhang·K. Yamada·I. Swainson·Hyunkyung Kim·R. J. Birgeneau
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Abstract

The dynamic spin susceptibility, $χ''(ω)$, has been measured over the energy range of $2 \leq ω\leq 10$ meV for overdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$. Incommensurate (IC) spin excitations are observed at 8 K for all superconducting samples for $0.25 \leq x \leq 0.28$ with $χ''$ peaking at $\sim 6$ meV. The IC peaks at 6 meV become smaller in intensity with increasing $x$ and, finally, become unobservable for a sample with $x=0.30$ which has no bulk superconductivity. The maximum $χ''$ decreases linearly with $T_c$(onset) in the overdoped region, implying a direct cooperative relation between the spin fluctuations and the superconductivity.

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S. Wakimoto, H. Zhang, K. Yamada, I. Swainson, Hyunkyung Kim, R. J. Birgeneau. 2004-06-29. Direct relation between the low-energy spin excitations and superconductivity of overdoped high-$T_c$ superconductors. https://doi.org/10.1103/physrevlett.92.217004

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