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