Van Hove Exciton-Cageons and High-T${}_c$ Superconductivity: VIIID Solitons and Nonlinear Dynamics

Abstract

The low-temperature orthorhombic (LTO) phase transition in La${}_{2-x}$Sr${}_x$CuO${}_4$ can be interpreted as a dynamic Jahn-Teller effect, in which the degenerate electronic states are associated with the large densities of states at the two van Hove singularities. The equations describing this phase are strongly nonlinear. This paper illustrates some consequences of the nonlinearity, by presenting a rich variety of exact nonlinear wave solutions for the model. Of particular interest are soliton lattice solutions: arrays of domain walls separating regions of local low-temperature tetragonal (LTT) symmetry. These arrays have a {\it macroscopic} average symmetry higher than LTT. These lattices can display either orthorhombic (`orthons') or tetragonal (`tetrons') symmetry, and can serve as models for a microscopic description of the dynamic JT LTO and high-temperature tetragonal phases, respectively.

17 pages plain TeX, 14 figures available upon request

Cited by in corpus (7)

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• Tunneling driven tilt modes of the O octahedra in La{2-x}Sr{x}CuO{4}: strong dependence on doping
• Van Hove Exciton-Cageons and High-T${}_c$ Superconductivity: XB: Polaronic Coupling in the Doped Material
• Van Hove Exciton-Cageons and High-T${}_c$ Superconductivity, XA: Role of Spin-Orbit Coupling in Generating a Diabolical Point
• Flux Phase as a Dynamic Jahn-Teller Phase: Berryonic Matter in the Cuprates?
• Modified BCS gap equation for Jahn-Teller distorted high temperature superconductors