  One type of order that has been observed to compete with superconductivity in
cuprates involves alternating charge and antiferromagnetic stripes. Recent
neutron scattering studies indicate that the magnetic excitation spectrum of a
stripe-ordered sample is very similar to that observed in superconducting
samples. In fact, it now appears that there may be a universal magnetic
spectrum for the cuprates. One likely implication of this universal spectrum is
that stripes of a dynamic form are present in the superconducting samples. On
cooling through the superconducting transition temperature, a gap opens in the
magnetic spectrum, and the weight lost at low energy piles up above the gap;
the transition temperature is correlated with the size of the spin gap.
Depending on the magnitude of the spin gap with respect to the magnetic
spectrum, the enhanced magnetic scattering at low temperature can be either
commensurate or incommensurate. Connections between stripe correlations and
superconductivity are discussed.
