Bose-Einstein condensation of strongly correlated electrons and phonons in cuprate superconductors

Abstract

The long-range Froehlich electron-phonon interaction has been identified as the most essential for pairing in high-temperature superconductors owing to poor screening, as is now confirmed by optical, isotope substitution, recent photoemission and some other measurements. I argue that low energy physics in cuprate superconductors is that of superlight small bipolarons, which are real-space hole pairs dressed by phonons in doped charge-transfer Mott insulators. They are itinerant quasiparticles existing in the Bloch states at low temperatures as also confirmed by continuous-time quantum Monte-Carlo algorithm (CTQMC) fully taking into account realistic Coulomb and long-range Froehlich interactions. Here I suggest that a parameter-free evaluation of Tc, unusual upper critical fields, the normal state Nernst effect, diamagnetism, the Hall-Lorenz numbers and giant proximity effects strongly support the three-dimensional (3D) Bose-Einstein condensation of mobile small bipolarons with zero off-diagonal order parameter above the resistive critical temperature Tc at variance with phase fluctuation scenarios of cuprates.

35 pages, 10 figures, to appear in the special volume of Journal of Physics: Condensed Matter

References in corpus (2)

• Hall-Lorenz number paradox in cuprate superconductors
• Comment on "Nernst effect in poor conductors and in the cuprate superconductors"

Cited by in corpus (6)

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• The impact of dynamical screening on the phonon dynamics of LaCuO
• Fermi blockade of the electron-phonon interaction: why strong coupling effects may not be seen in optimally doped high temperature superconductors
• Nature of extrinsic and intrinsic self-trapping of charge carriers in underdoped cuprate high-$T_{\text{c}}$ superconductors
• Bipolaronic proximity and other unconventional effects in cuprate superconductors