  We probe the superconducting gap in the zero temperature ground state of an
attractively interacting spin-imbalanced two-dimensional Fermi gas with
Diffusion Monte Carlo. A condensate fraction at nonzero pair momentum evidences
a spatially non-uniform superconducting order parameter. Comparison with exact
diagonalisation studies confirms that the nonzero condensate fraction across a
range of nonzero fermion pair momenta is consistent with non-exclusive pairing
between majority and minority fermions, an extension beyond FFLO theory.
