2007/10/03 by Satoh, Kohki H., Takeshita, Soshi, Koda, Akihiro +5
#FOS: Physical sciences #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.0710.0773
The microscopic details of flux line lattice state studied by muon spin rotation is reported in an electron-doped high-T\rm c cuprate superconductor, Sr1-xLaxCuO2 (SLCO, x=0.10--0.15). A clear sign of phase separation between magnetic and non-magnetic phases is observed, where the effective magnetic penetration depth [λ≡λ(T,H)] is determined selectively for the latter phase. The extremely small value of λ(0,0) %versus T\rm c and corresponding large superfluid density (ns ∝ λ-2) is consistent with presence of a large Fermi surface with carrier density of 1+x, which suggests the breakdown of the "doped Mott insulator" even at the "optimal doping" in SLCO. Moreover, a relatively weak anisotropy in the superconducting order parameter is suggested by the field dependence of λ(0,H). These observations strongly suggest that the superconductivity in SLCO is of a different class from hole-doped cuprates.