Anomalously Sharp Superconducting Transitions in Overdoped $L{a}_{2-x}S{r}_{x}Cu{O}_4$ Films

Abstract

We present measurements of $ab$-plane resistivity ${\rho }_{ab}(T)$ and superfluid density [$\propto {\lambda }^{-2}$, $\lambda$ = magnetic penetration depth] in $L{a}_{2-x}S{r}_{x}Cu{O}_4$ 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, ${\rho }_{ab}(T)$, ${\lambda }^{-2}(T)$, and transition temperature $T_c$ decrease, and upward curvature develops in ${\lambda }^{-2}(T)$. Given the sharp transitions, we interpret these results in the context of a homogeneous d-wave superconducting state, with elastic scattering that is enhanced relative to underdoped LSCO due to weaker electron correlations. This interpretation conflicts with the viewpoint that the overdoped state is inhomogeneous due to phase separation into superconducting and normal metal regions.

21 pages including 3 figures and 56 references. This version includes responses to referees and slight correction of data on two films. Conclusions the same as before

References in corpus (8)

• Scanning tunneling spectroscopy of high-temperature superconductors
• Progress and perspectives on the electron-doped cuprates
• The ground state of heavily-overdoped non-superconducting La${}_{2-x}$Sr${}_x$CuO${}_4$
• Quantum critical behaviour in the superfluid density of strongly underdoped ultrathin cuprate films
• Kosterlitz-Thouless behavior in layered superconductors: the role of the vortex-core energy
• Measurement of x-ray absorption spectra of overdoped high-temperature cuprate superconductors: Inapplicability of the single-band Hubbard model
• Negative Hall coefficients of heavily overdoped La2-xSrxCuO4
• Violation of the isotropic-$\ell$ approximation in overdoped La_{2-x}Sr_xCuO_4

Cited by in corpus (5)

• Locating the missing superconducting electrons in overdoped cuprates
• Disorder and superfluid density in overdoped cuprate superconductors
• Superconductor-to-Metal Quantum Phase Transition in Overdoped $L{a}_{2-x}S{r}_{x}Cu{O}_4$
• Strongly-overdoped La${}_{2-x}$Sr${}_x$CuO${}_4$: Evidence for Josephson-coupled grains of strongly-correlated superconductor
• Effect of radiation-induced defects on the superfluid density and optical conductivity of overdoped La${}_{2-x}$Sr${}_x$CuO${}_4$