Models of spin structures of Sr2RuO4
  The mean field study of bands and the Fermi surfaces (FS's) are carried out for 3-band model of ruthenate. In particular, the lowest spiral state with incommensurate vector Q=2\pi(1/3,1/3) corresponding to nesting of bands display a set of FS's around electro pockets and shadow sheets along $\Gamma-M$ lines. The latter may provide a new interpretation of the dispersionless peaks (so called SS features) observed in photoemission. For spiral state the polarisation asymmetry of the photoemission intensity is revealed. The calculated spin susceptibility for this state describes the low frequency magnetic peak at q=Q observed in neutron scattering. 
A. A. Ovchinnikov, M. Ya. Ovchinnikova