• Tromp, Willem O.
• Smit, Steef
• Van Heumen, Erik
• Takeuchi, Tsunehiro
• Ge, Jian-Feng
• Kondo, Takeshi
• Allan, Milan
• Bastiaans, Koen M.
• Benschop, Tjerk
• Yin, Yi
• Battisti, Irene
• Vervloet, Amber H. M.
• Chatzopoulos, Damianos
• Huang, Yinkai
• Sulangi, Miguel Antonio
• Zaanen, Jan
• Golden, Mark

Abstract

<jats:title>Abstract</jats:title><jats:p>The cuprate high-temperature superconductors exhibit many unexplained electronic phases, but the superconductivity at high doping is often believed to be governed by conventional mean-field Bardeen–Cooper–Schrieffer theory<jats:sup>1</jats:sup>. However, it was shown that the superfluid density vanishes when the transition temperature goes to zero<jats:sup>2,3</jats:sup>, in contradiction to expectations from Bardeen–Cooper–Schrieffer theory. Our scanning tunnelling spectroscopy measurements in the overdoped regime of the (Pb,Bi)<jats:sub>2</jats:sub>Sr<jats:sub>2</jats:sub>CuO<jats:sub>6+<jats:italic>δ</jats:italic></jats:sub> high-temperature superconductor show that this is due to the emergence of nanoscale superconducting puddles in a metallic matrix<jats:sup>4,5</jats:sup>. Our measurements further reveal that this puddling is driven by gap filling instead of gap closing. The important implication is that it is not a diminishing pairing interaction that causes the breakdown of superconductivity. Unexpectedly, the measured gap-to-filling correlation also reveals that pair breaking by disorder does not play a dominant role and that the mechanism of superconductivity in overdoped cuprate superconductors is qualitatively different from conventional mean-field theory.</jats:p>

Topics

• density
• impedance spectroscopy
• phase
• theory
• superconductivity
• superconductivity
• scanning tunnelling spectroscopy