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Nature. 2016 Aug 18;536(7616):309-11. doi: 10.1038/nature19061.

Dependence of the critical temperature in overdoped copper oxides on superfluid density.

Nature

I Božović, X He, J Wu, A T Bollinger

Affiliations

  1. Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
  2. Applied Physics Department, Yale University, New Haven, Connecticut 06520, USA.

PMID: 27535534 DOI: 10.1038/nature19061

Abstract

The physics of underdoped copper oxide superconductors, including the pseudogap, spin and charge ordering and their relation to superconductivity, is intensely debated. The overdoped copper oxides are perceived as simpler, with strongly correlated fermion physics evolving smoothly into the conventional Bardeen-Cooper-Schrieffer behaviour. Pioneering studies on a few overdoped samples indicated that the superfluid density was much lower than expected, but this was attributed to pair-breaking, disorder and phase separation. Here we report the way in which the magnetic penetration depth and the phase stiffness depend on temperature and doping by investigating the entire overdoped side of the La2-xSrxCuO4 phase diagram. We measured the absolute values of the magnetic penetration depth and the phase stiffness to an accuracy of one per cent in thousands of samples; the large statistics reveal clear trends and intrinsic properties. The films are homogeneous; variations in the critical superconducting temperature within a film are very small (less than one kelvin). At every level of doping the phase stiffness decreases linearly with temperature. The dependence of the zero-temperature phase stiffness on the critical superconducting temperature is generally linear, but with an offset; however, close to the origin this dependence becomes parabolic. This scaling law is incompatible with the standard Bardeen-Cooper-Schrieffer description.

References

  1. Nature. 2015 Feb 12;518(7538):179-86 - PubMed
  2. Rev Sci Instrum. 2014 Oct;85(10):103902 - PubMed
  3. Nature. 2011 Apr 28;472(7344):458-60 - PubMed
  4. Rev Sci Instrum. 2014 Jul;85(7):073905 - PubMed
  5. Phys Rev Lett. 1989 May 8;62(19):2317-2320 - PubMed
  6. Phys Rev B Condens Matter. 1993 Aug 1;48(6):4219-4222 - PubMed
  7. Phys Rev B Condens Matter. 1992 Dec 1;46(22):14662-14674 - PubMed
  8. Science. 2009 Oct 30;326(5953):699-702 - PubMed
  9. Nat Commun. 2011;2:272 - PubMed
  10. Phys Rev B Condens Matter. 1995 Oct 1;52(14):10488-10498 - PubMed
  11. Phys Rev Lett. 1993 Sep 13;71(11):1764-1767 - PubMed
  12. Phys Rev B Condens Matter. 1996 Aug 1;54(5):3530-3544 - PubMed
  13. Nature. 2008 Oct 9;455(7214):782-5 - PubMed
  14. Phys Rev B Condens Matter. 1996 Jun 1;53(22):R14745-R14748 - PubMed
  15. Phys Rev Lett. 2002 Sep 2;89(10):107001 - PubMed
  16. Phys Rev Lett. 2006 Jun 9;96(22):227002 - PubMed
  17. Phys Rev B Condens Matter. 1996 Sep 1;54(10):7481-7488 - PubMed
  18. Nature. 2004 Jul 29;430(6999):539-41 - PubMed
  19. Science. 2009 Jan 30;323(5914):603-7 - PubMed
  20. Phys Rev Lett. 2007 Dec 7;99(23):237003 - PubMed
  21. Nat Mater. 2013 Oct;12(10):877-81 - PubMed
  22. Nature. 2004 Jul 29;430(6999):512-3 - PubMed

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