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
2-q
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
pursuant upon the falling level of charge stripe organization under excitation.