Puddle formation and persistent gaps across the non-mean-field breakdown of superconductivity in overdoped (Pb,Bi)2Sr2CuO6+δ

Willem O Tromp; Tjerk Benschop; Jian-Feng Ge; Irene Battisti; Koen M Bastiaans; Damianos Chatzopoulos; Amber H M Vervloet; Steef Smit; Erik van Heumen; Mark S Golden; Yinkai Huang; Takeshi Kondo; Tsunehiro Takeuchi; Yi Yin; Jennifer E Hoffman; Miguel Antonio Sulangi; Jan Zaanen; Milan P Allan

doi:10.1038/s41563-023-01497-1

Puddle formation and persistent gaps across the non-mean-field breakdown of superconductivity in overdoped (Pb,Bi)₂Sr₂CuO_6+δ

Nat Mater. 2023 Jun;22(6):703-709. doi: 10.1038/s41563-023-01497-1. Epub 2023 Mar 6.

Authors

Willem O Tromp^#¹, Tjerk Benschop^#¹, Jian-Feng Ge¹, Irene Battisti¹, Koen M Bastiaans^{1

2}, Damianos Chatzopoulos¹, Amber H M Vervloet¹, Steef Smit³, Erik van Heumen^{3

4}, Mark S Golden³, Yinkai Huang³, Takeshi Kondo⁵, Tsunehiro Takeuchi⁶, Yi Yin^{7

8}, Jennifer E Hoffman⁹, Miguel Antonio Sulangi^{10

11}, Jan Zaanen¹², Milan P Allan¹³

Affiliations

¹ Leiden Institute of Physics, Leiden University, Leiden, The Netherlands.
² Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
³ Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands.
⁴ QuSoft, Amsterdam, The Netherlands.
⁵ Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan.
⁶ Toyota Technological Institute, Nagoya, Japan.
⁷ Zhejiang Province Key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou, China.
⁸ Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjiang, China.
⁹ Department of Physics, Harvard University, Cambridge, MA, USA.
¹⁰ Department of Physics, University of Florida, Gainesville, FL, USA.
¹¹ National Institute of Physics, College of Science, University of the Philippines, Diliman, Quezon City, Philippines.
¹² Institute-Lorentz for Theoretical Physics, Leiden University, Leiden, The Netherlands.
¹³ Leiden Institute of Physics, Leiden University, Leiden, The Netherlands. [email protected].

^# Contributed equally.

Abstract

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 theory¹. However, it was shown that the superfluid density vanishes when the transition temperature goes to zero^2,3, in contradiction to expectations from Bardeen-Cooper-Schrieffer theory. Our scanning tunnelling spectroscopy measurements in the overdoped regime of the (Pb,Bi)₂Sr₂CuO_6+δ high-temperature superconductor show that this is due to the emergence of nanoscale superconducting puddles in a metallic matrix^4,5. 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.

Abstract

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