Phase fluctuations and the pseudogap in YBa(2)Cu(3)O (x)

C Meingast; V Pasler; P Nagel; A Rykov; S Tajima; P Olsson

doi:10.1103/PhysRevLett.86.1606

Phase fluctuations and the pseudogap in YBa(2)Cu(3)O (x)

Phys Rev Lett. 2001 Feb 19;86(8):1606-9. doi: 10.1103/PhysRevLett.86.1606.

Authors

C Meingast¹, V Pasler, P Nagel, A Rykov, S Tajima, P Olsson

Affiliation

¹ Forschungszentrum Karlsruhe, Institut für Festkörperphysik, Karlsruhe, Germany.

PMID: 11290204
DOI: 10.1103/PhysRevLett.86.1606

Abstract

The thermodynamics of the superconducting transition is studied as a function of doping using high-resolution expansivity data of YBa(2)Cu(3)O (x) single crystals and Monte Carlo simulations of the anisotropic 3D- XY model. We directly show that T(c) of underdoped YBa(2)Cu(3)O (x) is strongly suppressed from its mean-field value (T(MF)(c)) by phase fluctuations of the superconducting order parameter. For overdoped YBa(2)Cu(3)O (x) fluctuation effects are greatly reduced and T(c) approximately T(MF)(c). We find that T(MF)(c) exhibits a similar doping dependence as the pseudogap energy, naturally suggesting that the pseudogap arises from phase-incoherent Cooper pairing.