We consider the reconstruction expected for the Fermi surface of underdoped
YBa2Cu3O6+x in the case of a collinear spin-density wave with a characteristic
vector Q=(pi[1+/-2 delta],pi), assuming an incommensurability delta~0.06
similar to that found in recent neutron scattering experiments. A Fermi surface
possibly consistent with the multiple observed quantum oscillation frequencies
is obtained. From the low band masses expected using this model as compared
with experiment, a uniform enhancement of the quasiparticle effective mass over
the Fermi surface by a factor of ~7 is indicated. Further predictions of the
Fermi surface topology are made, which may potentially be tested by experiment
to indicate the relevance of this model to underdoped YBa2Cu3O6+x.Comment:
