  We perform three-dimensional smoothed particle hydrodynamics simulations in a
realistic cosmological setting to investigate the expansion, feedback, and
chemical enrichment properties of a 200 M_sun pair-instability supernova in the
high-redshift universe. We find that the SN remnant propagates for a Hubble
time at z = 20 to a final mass-weighted mean shock radius of 2.5 kpc (proper),
roughly half the size of the HII region, and in this process sweeps up a total
gas mass of 2.5*10^5 M_sun. The morphology of the shock becomes highly
anisotropic once it leaves the host halo and encounters filaments and
neighboring minihalos, while the bulk of the shock propagates into the voids of
the intergalactic medium. The SN entirely disrupts the host halo and terminates
further star formation for at least 200 Myr, while in our specific case it
exerts positive mechanical feedback on neighboring minihalos by
shock-compressing their cores. In contrast, we do not observe secondary star
formation in the dense shell via gravitational fragmentation, due to the
previous photoheating by the progenitor star. We find that cooling by metal
lines is unimportant for the entire evolution of the SN remnant, while the
metal-enriched, interior bubble expands adiabatically into the cavities created
by the shock, and ultimately into the voids with a maximum extent similar to
the final mass-weighted mean shock radius. Finally, we conclude that dark
matter halos of at least M_vir > 10^8 M_sun must be assembled to recollect all
components of the swept-up gas.
