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Two Pseudogaps in the Cuprates: Meingast et al. Reply

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

In classical superconductors Cooper-pair formation and phase coherence occur simultaneously as the temperature is lowered below Tc. In high-temperature superconductors (HTSC), on the other hand, the small superfluid density and low associated phase stiffness of the superconducting condensate are expected to lead to a separation of the Cooper-pair formation and the phase-coherence temperatures, especially in underdoped materials [3]. The only real phase transition in this scenario is the 3d-XY phase-ordering transition at Tc [3,4]. In our Letter [2] we showed that Tc in underdoped and optimally doped YBCO is just such a phase-ordering temperature, and then the question naturally arises - where do the Cooper pairs form? The observed 3d-XY scaling of our thermal expansion data over a wide temperature range [2] suggests that pairing occurs at temperatures considerably above Tc, and it thus appeared quite natural for us to associate the opening of the pseudogap at T*.

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C. Meingast, V. Pasler, P. Nagel, A. Rykov, S. Tajima, P. Olsson. 2003-07-09. Two Pseudogaps in the Cuprates: Meingast et al. Reply. https://doi.org/10.1103/physrevlett.89.229704

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