Tuning of Scattering Resonances by Time-Periodic Driving

Scattering by a short-range inter-particle potential with time-periodic modulation is investigated with Floquet theory without assuming any high frequency approximations. For a harmonic drive it turns out that strong resonances occur, which allow versatile tuning of the s-wave scattering length and the resonance width by adjusting frequency and driving amplitude. Our approach leads to a simple description of the effect in terms of a generalized Fano-Anderson model, which in turn identifies the physical origin and leads to an analytic quantitative description of the resonances. Results for general experimental situations of magnetic and optical driving using two coupled channels and including higher harmonics are discussed.