Muon-Spin-Rotation Measurements of the Penetration Depth of the Infinite-Layer Electron-Doped Sr_(0.9)La_(0.1)CuO_2 Cuprate Superconductor

摘要

Muon-spin-rotation (μSR) measurements of the in-plane penetration depth λ_(ab) have been performed in the infinite-layer electron-doped Sr_(0.9)La_(0.1)CuO_2 high-T_c superconductor (HTS). Absence of the magnetic rare-earth ions in this compound allowed us to measure for the first time the absolute value of λ_(ab)(0) in electron-doped HTSs using μSR. We found λ_(ab) (0) = 116(2) nm. The zero-temperature depolarization rate σ(0) ∝ 1/λ_(ab)~2(0) = 4.6(1) μs~(-1) is more than 4 times higher than expected from the Uemura line. Therefore, this electron-doped HTS does not follow the Uemura relation found for hole-doped HTSs.