Structural matters in HTSC; the origin and form of stripe organization and checker boarding

TL;DR

This paper explores the role of stripe and checkerboard charge and spin organization in high-temperature superconductors, proposing models that reconcile experimental data and highlight the importance of real-space hole arrangements.

Contribution

It introduces 2q diagonal stripe models compatible with various experimental observations and links specific doping levels to superconducting properties within a boson-fermion framework.

Findings

Stripe models are 2q and diagonal, with face-centered charge and spin arrays.

Checkerboarding is linked to correlation-driven Fermi surface collapse.

Incommensurate spin diffraction is driven by charge and strain, not spin-wave physics.

Abstract

The paper deals with the controversial charge and spin self-organization phenomena in the HTSC cuprates, of which neutron, X-ray, STM and ARPES experiments give complementary, sometimes apparently contradictory glimpses. The examination has been set in the context of the boson-fermion, negative-U understanding of HTSC advocated over many years by the author. Stripe models are developed which are 2q in nature and diagonal in form. For such a geometry to be compatible with the data rests upon both the spin and charge arrays being face-centred. Various special doping concentrations are closely looked at, in particular p = 0.1836 or 9/49, which is associated with the maximization of the superconducting condensation energy and the termination of the pseudogap regime. The stripe models are dictated by real space organization of the holes, whereas the dispersionless checkerboarding is interpreted in terms of correlation driven collapse of normal Fermi surface behaviour and response functions. The incommensurate spin diffraction below the resonance energy is seen as in no way expressing spin-wave physics or Fermi surface nesting, but is driven by charge and strain (Jahn-Teller) considerations, and it stands virtually without dispersion. The apparent dispersion comes from the downward dispersion of the resonance peak, and the growth of a further incoherent commensurate peak ensuing from the falling level of charge stripe organization under excitation.