Fragmentation of bands and the Fermi surfaces in stripe phases

Abstract

The mean-field study of the stripe phases of t-t'-U Hubbard model confirms formation of the "impurity" subbands of states localized on domain walls. For bond-aligned stripes it is shown that segments of the Fermi surfaces (FS) in antinodal and nodal directions correspond to the "impurity" band or to that delocalized over a whole antiferromagnet domain. This might explain the dichotomy between corresponding quasiparticles in La_{2-x}Sr_xCuO_4. The Fermi surface changes its topology at some doping depending on stripe width. Additional ordering at the domain walls should be supposed to accord the observed 1/8 anomaly and the stripe spacing. It is confirmed also that the diagonal stripes can provide the dielectric state at nonzero doping.