Pairing Symmetry Studied from Impurity Effects in the Undoped Superconductor T'-La${}_{1.8}$Eu${}_{0.2}$CuO${}_4$

Abstract

We have investigated the effects of magnetic Ni and nonmagnetic Zn impurities on the superconductivity in undoped T'-La${}_{1.8}$Eu${}_{0.2}$CuO${}_4$ (T'-LECO) with the Nd${}_2$CuO${}_4$-type structure, using the polycrystalline bulk samples, to clarify the pairing symmetry. It has been found that both suppression rates of the superconducting transition temperature $T_{\mathrm{c}}$ by Ni and Zn impurities are nearly the same and are very similar to those in the optimally doped and overdoped regimes of hole-doped T-La${}_{2-x}$Sr${}_x$CuO${}_4$ with the K${}_2$NiF${}_4$-type structure. These results strongly suggest that the superconductivity in undoped T'-LECO is of the $d$-wave symmetry and is mediated by the spin fluctuation.

13 pages, 4 figures, accepted for publication in Journal of the Physical Society of Japan

References in corpus (4)

• Hole-Doped Cuprate High Temperature Superconductors
• Bulk superconductivity in undoped T'-La${}_{1.9}$Y${}_{0.1}$CuO${}_4$ probed by muon spin rotation
• Optical study of superconducting Pr${}_2$CuO${}_x$ with $x\simeq 4$
• Eliashberg analysis of the optical conductivity in superconducting Pr${}_2$CuO${}_x$ ($x\simeq 4$)

Cited by in corpus (3)

• Novel Electronic State and Superconductivity in the Electron-Doped High-Tc T'-Superconductors
• Electronic State of T'-Pr${}_{1.3-x}$La${}_{0.7}$Ce${}_x$CuO${}_4$ ($x=0.10$) Studied by Compton Scattering
• Cu-spin Correlation in the Electron-overdoped High-Tc Cuprate Thin Films of La_2-x_Ce_x_CuO_4_ Probed by Low-energy Muons