Manipulating the scattering length of a Bose - Einstein condensate in an   amplitude - modulated optical lattice
  The scattering length in a BEC confined in an amplitude - modulated optical lattice can be manipulated by the modulation strength. Two standing laser waves of main and sideband frequencies of an optical lattice induce a Raman transition; due to resonant Raman driving the effective scattering length depends on the modulation strength and the detuning from resonance and can be tuned to a given value. 
G. M. Genkin