How can we relate the critical temperature and the superconducting gap amplitude in cuprate superconductors?

ORAL

Abstract

We explore the superconducting state of hole-doped cuprates by electronic Raman scattering as a function of both temperature and doping level. We observe a loss of coherent quasi-particles in the anti-nodal region and show that coherent Bogoliubov quasiparticles are confined around the nodes. This contrasts to conventional superconductors where superconductivity develops uniformly along the normal-state Fermi surface. We define the fraction of coherent Fermi surface, f$_{c}$ around the nodes for which quasi-particles are well defined and superconductivity sets in. We establish that T$_{c} \quad \propto $ f$_{c}\Delta _{max}$. $\Delta _{max}$ is the maximum amplitude of the d-wave superconducting gap. This new relation differs from the standard BCS theory and gives us some clues for increasing T$_{c}$ in the cuprates. S. Blanc et al. Phys. Rev. B \textbf{82}, 144516 (2010); S. Blanc et al. Phys. Rev. B \textbf{80}, 140502 (2009).

–

Authors

  • Alain Sacuto

    • Laboratoire Mat\'eriaux et Ph\'enom\`enes Quantiques, CNRS Universit\'e Paris Diderot - Paris 7, Paris Cedex 13, France
    • Universite Paris Diderot
    • Laboratoire Materiaux et Phenomenes Quantiques - Paris 7
    • Laboratoire Materiaux et Phenomenes Quantiques UMR 7162 CNRS Universite Paris Diderot, Paris, France

  • Seabstien Blanc

    • Laboratoire Mat\'eriaux et Ph\'enom\`enes Quantiques, CNRS Universit\'e Paris Diderot - Paris 7, Paris Cedex 13, France

  • Yann Gallais

    • Laboratoire Mat\'eriaux et Ph\'enom\`enes Quantiques, CNRS Universit\'e Paris Diderot - Paris 7, Paris Cedex 13, France

  • Maximilien Cazayous

    • Laboratoire Mat\'eriaux et Ph\'enom\`enes Quantiques, CNRS Universit\'e Paris Diderot - Paris 7, Paris Cedex 13, France

  • Marie Aude Measson

    • Laboratoire Mat\'eriaux et Ph\'enom\`enes Quantiques, CNRS Universit\'e Paris Diderot - Paris 7, Paris Cedex 13, France

  • J.S. Wen

    • Matter Physics and Materials Science, Brookhaven National Laboratory (BNL), USA

  • Z.J. Xu

    • Matter Physics and Materials Science, Brookhaven National Laboratory (BNL), USA

  • Genda Gu

    • Matter Physics and Materials Science, Brookhaven National Laboratory (BNL), USA