  We consider defect mediated melting of Fulde-Ferrell-Larkin-Ovchinnikov
(FFLO) and pair density wave (PDW) phases in two dimensions. Examining
mean-field ground states in which the spatial oscillations of the FFLO/PDW
superfluid order parameter exhibit hexagonal lattice symmetry, we find that
thermal melting leads to a variety of novel phases. We find that a spatially
homogeneous charge six superfluid can arise from melting a hexagonal
vortex-anitvortex lattice FFLO/PDW phase. The charge six superfluid has an
order parameter corresponding to a bound state of six fermions. We further find
that a hexagonal vortex-free FFLO/PDW phase can melt to yield a conventional
(charge two) homogeneous superfluid. A key role is played by topological
defects that combine fractional vortices of the superfluid order and fractional
dislocations of the lattice order.
