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Phase fluctuations and the pseudogap in YBa2Cu3Ox

C. Meingast·V. Pasler·P. Nagel·A. Rykov·S. Tajima·P. Olsson
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Abstract

The thermodynamics of the superconducting transition is studied as a function of doping using high-resolution expansivity data of YBa2Cu3Ox single crystals and Monte-Carlo simulations of the anisotropic 3D-XY model. We directly show that Tc of underdoped YBa2Cu3Ox is strongly suppressed from its mean-field value (Tc-MF) by phase fluctuations of the superconducting order parameter. For overdoped YBa2Cu3Ox fluctuation effects are greatly reduced and Tc ~ Tc-MF . We find that Tc-MF exhibits a similar doping dependence as the pseudogap energy, naturally suggesting that the pseudogap arises from phase-incoherent Cooper pairing.

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C. Meingast, V. Pasler, P. Nagel, A. Rykov, S. Tajima, P. Olsson. 2000-12-12. Phase fluctuations and the pseudogap in YBa2Cu3Ox. https://doi.org/10.1103/physrevlett.86.1606

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