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Distinct doping dependences of the pseudogap and superconducting gap La$_{2-x}$Sr$_{x}$CuO$_4$ cuprate superconductors

M. Hashimoto·T. Yoshida·K. Tanaka·A. Fujimori·M. Okusawa·S. Wakimoto·K. Yamada·T. Kakeshita·H. Eisaki·S. Uchida
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Abstract

We have performed a temperature-dependent angle-integrated photoemission study of lightly-doped to heavily-overdoped La$_{2-x}$Sr$_{x}$CuO$_4$ and oxygen-doped La$_2$CuO$_{4.10}$. We found that both the magnitude $Δ$* of the (small) pseudogap and the temperature \textit{T}* at which the pseudogap is opened increases with decreasing hole concentration, consistent with previous studies. On the other hand, the superconducting gap $Δ_{sc}$ was found to remain small for decreasing hole concentration. The results can be explained if the superconducting gap opens only on the Fermi arc around the nodal (0,0)-($π,π$) direction while the pseudogap opens around $\sim$($π$, 0).

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M. Hashimoto, T. Yoshida, K. Tanaka, A. Fujimori, M. Okusawa, S. Wakimoto, K. Yamada, T. Kakeshita, H. Eisaki, S. Uchida. 2007-04-16. Distinct doping dependences of the pseudogap and superconducting gap La$_{2-x}$Sr$_{x}$CuO$_4$ cuprate superconductors. https://doi.org/10.1103/physrevb.75.140503

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