Fast frictionless expansion of an optical lattice

We investigate fast frictionless expansion of an optical lattice with dynamically variable spacing (accordion lattice). We design an expansion trajectory that yields a final state identical to the initial state up to an irrelevant phase factor. We discuss the effect of additional force and nonlinear interaction on the fast frictionless expansion.

► We give the conditions for superadiabatic expansion for an optical lattice.
► We show that superadiabacity is possible in the presence of nonlinear interaction.
► We propose an experiment to achieve fast frictionless expansion in few milliseconds.
► We argue that frictionless expansion allows imaging of the atoms at individual sites.