Fragmentation of band and Fermi surface in stripe phaseM. Ya. Ovchinnikova
Institute of Chemical Physics, RAS - Moscow, 119977, Kosygin str., 4, Russia
received 10 September 2004; accepted in final form 18 November 2004
published online 12 January 2005
The mean-field study of the stripe phases of the t- t'- U Hubbard model confirms the formation of the in-gap subbands of states localized on the domain walls. For bond-aligned stripes it is shown that segments of Fermi surfaces in antinodal and nodal directions correspond to the in-gap band or to that delocalized over a whole antiferromagnet domain. This can explain the dichotomy between the corresponding quasiparticles in 2-x x 4 (LSCO) and the suppression of spectral weight in the nodal direction in underdoped LSCO. The Fermi surface changes its topology with doping. It is confirmed also that diagonal stripes can provide an insulating state at nonzero doping.
71.10.Fd - Lattice fermion models (Hubbard model, etc.).
74.20.Rp - Pairing symmetries (other than s-wave).
74.20.-z - Theories and models of superconducting state.
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