  We investigate the properties of entanglement in one-dimensional fermionic
lattices at the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid regime. By
analyzing occupation probabilities, which are concepts closely related to FFLO
and entanglement, we obtain approximate analytical expressions for the
spin-flip processes at the FFLO regime. We also apply density matrix
renormalization group calculations to obtain the exact ground-state
entanglement of the system in superfluid and non-superfluid regimes. Our
results reveal a breaking pairs avalanche appearing precisely at the
FFLO-normal phase transition. We find that entanglement is non-monotonic in
superfluid regimes, feature that could be used as a signature of exotic
superfluidity.
