  We theoretically investigate the feasibility of applying spin squeezing to a
light pulse atom interferometer in the presence of large momentum transfer
using off-resonant Raman transitions, in order to enhance the sensitivity of
accelerometry close to the Heisenberg limit. We also show how to implement this
scheme in a dual-species atom interferometer for precision test of the
equivalence principle by measuring the Eotvos parameter, and identify the spin
squeezing protocol that is best suited for such an experiment. For a space
borne platform in low earth orbit, such a scheme may eventually enable the
measurement of the Eotvos parameter with a sensitivity of the order of
10^(-20).
