Transverse collisional instabilities of a Bose-Einstein condensate in a driven one-dimensional lattice

Understand

Motivated by recent experiments, we analyse the stability of a three-dimensional Bose-Einstein condensate (BEC) loaded in a periodically driven one-dimensional optical lattice.

• Such periodically driven systems do not have a thermodynamic ground state, but may have a long-lived steady state which is an eigenstate of a "Floquet Hamiltonian".
• We explore collisional instabilities of the Floquet ground state which transfer energy into the transverse modes.
• We calculate decay rates, finding that the lifetime scales as the inverse square of the scattering length and inverse of the peak three- dimensional density.