Ordering of bond length fluctuations in the copper-oxide superconductors
Texas Materials Institute, ETC 9.102, University of
Texas at Austin Austin, TX 78712, USA
Accepted: 19 November 2001
The phase diagram of x is interpreted. From the virial theorem, it is argued that the crossover from localized to itinerant electronic behavior in the range 0 < x < 0.3 is first order, and cooperative bond length fluctuations give spinodal phase segregations below room temperature between the superconductive phase at 0.15 < x < 0.18 and either the parent, antiferromagnetic phase at x = 0 or the overdoped phase x > 0.25. In the interval 0.1 < x < 0.27, the short-length-scale bond length fluctuations between strongly and weakly correlated regions order progressively with decreasing temperature T < 300 into static or travelling CDW/SDW stripes corresponding to x = 1/8, 1/6, 5/24, or 1/4. Hybridization of itinerant electrons with a traveling x = 1/6 CDW/SDW gives the heavy fermions that condense into superconductive pairs.
PACS: 72.80.Ga – Transition-metal compounds / 74.20.Mn – Superconductivity: Nonconventional mechanisms (spin fluctuations, polarons and bipolarons, resonating valence bond model, anyon mechanism, marginal Fermi liquid, Luttinger liquid, etc.) / 74.72.Dn – La-based cuprates
© EDP Sciences, 2002