Sum rule analysis of YBa$_2$Cu$_3$O$_y$ in magnetic field

ORAL

Abstract

We present infrared magneto-optical reflectance measurements which characterize the interplane transport of three dopings of YBa$_2$Cu$_3$O$_y$. An optical sum rule analysis reveals the field-evolution of the energy scale from which the superconducting condensate is drawn. We find that fields applied parallel to the $c$ axis totally suppress high-energy contributions to the condensate in underdoped samples while only moderately reducing the superfluid density. For optimally doped crystals the sum rule is satisfied and not modified by field. These results point toward a more conventional, BCS-like condensation mechanism, and will be discussed in relation to the interlayer phase coherence.

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Authors

  • Andrew LaForge

    Univ. of California, San Diego, Department of Physics, University of California, San Diego

  • Willie Padilla

    Boston College

  • Kenneth Burch

    Los Alamos National Laboratory

  • Zhiqiang Li

    University of California, San Diego, Univ. of California, San Diego

  • Alexander Schafgans

    Univ. of California, San Diego, Department of Physics, University of California, San Diego

  • Kouji Segawa

    Osaka University, Japan

  • Yoichi Ando

    Osaka University, Japan

  • Dimitri Basov

    Univ. of California, San Diego, University of California San Diego, Department of Physics, University of California, San Diego, University of California, San Diego, University of California at San Diego