  The two-orbital Hubbard model for the pnictides is studied numerically using
the real-space Hartree-Fock approximation on finite clusters. Upon electron
doping, states with a nonuniform distribution of charge are stabilized. The
observed patterns correspond to charge stripes oriented perpendicular to the
direction of the spin stripes of the undoped magnetic ground state. While these
charge striped states are robust when the undoped state has a Hubbard gap,
their existence when the intermediate-coupling magnetic metallic state of
pnictides is doped was also observed for particular model parameters. Results
for hole doping and implications for recent experiments that reported
electronic nematic states and spin incommensurability are also briefly
discussed.
