  Correlation in temperature behavior of the optical, neutron, and muon
experimental data is established for YBa2Cu3O6+x in both the pseudogap state at
Tc<T<T* and the superconducting state at T<Tc. We have showed that our
absorption spectra measured in the vicinity of the optical gap are very
sensitive to the development of antiferromagnetic fluctuations and to the
formation of a stripe structure. The inelastic neutron scattering and
zero-field muon spin relaxation data analyzed in this paper were taken from the
measurements made by Dai et al. and Sonier et al., respectively. Comparative
analysis of the independent results could be very helpful in understanding the
interrelation of superconductivity and antiferromagnetism in cuprate
superconductors.
