Superfluid and normal-fluid densities in the high-Tc superconductors

D. B. Tanner, F. Gao, K. Kamarás, Hsiang Lin Liu, M. A. Quijada, D. B. Romero, Y. D. Yoon, A. Zibold, H. Berger, G. Margaritondo, L. Forró, R. J. Kelly, M. Onellion, G. Cao, J. E. Crow, O. Beom-Hoan, J. T. Markert, J. P. Rice, D. M. Ginsberg, T. Wolf

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In clean metallic superconductors, 100% of the mobile carriers participate in the condensate, so that the London penetration depth (which measures the electromagnetic screening by the superconductor) indicates charge densities comparable to those inferred from the free-carrier plasma frequency. In the cuprates, this is not the case, even though penetration depth measurements have shown a good correlation between superfluid density and superconducting transition temperature in the underdoped-to-optimally-doped part of the phase diagram. Optical measurements, which permit independent determination of the total doping-induced spectral weight and the superfluid density, show that in optimally doped materials only about 20% of the doping-induced spectral weight joins the superfluid. The rest remains in finite-frequency, midinfrared absorption. In underdoped materials, the superfluid fraction is even smaller. This result implies extremely strong coupling for these superconductors.

Original languageEnglish
Pages (from-to)2193-2196
Number of pages4
JournalPhysica C: Superconductivity and its applications
Volume341-348 (IV)
Publication statusPublished - 2000 Jan 1


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Cite this

Tanner, D. B., Gao, F., Kamarás, K., Liu, H. L., Quijada, M. A., Romero, D. B., Yoon, Y. D., Zibold, A., Berger, H., Margaritondo, G., Forró, L., Kelly, R. J., Onellion, M., Cao, G., Crow, J. E., Beom-Hoan, O., Markert, J. T., Rice, J. P., Ginsberg, D. M., & Wolf, T. (2000). Superfluid and normal-fluid densities in the high-Tc superconductors. Physica C: Superconductivity and its applications, 341-348 (IV), 2193-2196.