Anomalously sharp superconducting transitions in overdoped La2-xSrxCuO4 films

作者：Lemberger T R^*; Hetel I; Tsukada A; Naito M

来源：Physical Review B, 2010, 82(21): 214513.

DOI：10.1103/PhysRevB.82.214513

We present measurements of ab-plane resistivity rho(ab)(T) and superfluid density (n(s) proportional to lambda(-2), lambda = magnetic penetration depth) in La2-xSrxCuO4 (LSCO) films. As Sr concentration x exceeds about 0.22, the superconducting transition sharpens dramatically, becoming as narrow as 200 mK near the super-to-normal-metal quantum critical point. At the same time, lambda(-2)(0) and transition temperature T-c decrease, and upward curvature develops in lambda T-2(). Given the sharp transitions, we interpret these results in the context of a homogeneous d-wave superconducting state, not a phase-separated state, with elastic scattering that is enhanced relative to underdoped LSCO due to weaker electron correlations.

• 出版日期2010-12-16