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arXiv · 2009.10932

Superconducting fluctuations in overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$

Yu He·Su-Di Chen·Zi-Xiang Li·Dan Zhao·Dongjoon Song·Yoshiyuki Yoshida·Hiroshi Eisaki·Tao Wu·Xian-Hui Chen·Dong-Hui Lu·Christoph Meingast·Thomas P. Devereaux·Robert J. Birgeneau·Makoto Hashimoto·Dung-Hai Lee·Zhi-Xun Shen
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Abstract

Fluctuating superconductivity - vestigial Cooper pairing in the resistive state of a material - is usually associated with low dimensionality, strong disorder or low carrier density. Here, we report single particle spectroscopic, thermodynamic and magnetic evidence for persistent superconducting fluctuations in heavily hole-doped cuprate superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ ($T_c$ = 66~K) despite the high carrier density. With a sign-problem free quantum Monte Carlo calculation, we show how a partially flat band at ($π$,0) can help enhance superconducting phase fluctuations. Finally, we discuss the implications of an anisotropic band structure on the phase-coherence-limited superconductivity in overdoped cuprates and other superconductors.

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Yu He, Su-Di Chen, Zi-Xiang Li, Dan Zhao, Dongjoon Song, Yoshiyuki Yoshida, Hiroshi Eisaki, Tao Wu, Xian-Hui Chen, Dong-Hui Lu, Christoph Meingast, Thomas P. Devereaux, Robert J. Birgeneau, Makoto Hashimoto, Dung-Hai Lee, Zhi-Xun Shen. 2021-04-17. Superconducting fluctuations in overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$. https://doi.org/10.1103/physrevx.11.031068

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