Rabi-resonant behavior of periodically-driven correlated fermion systems

Fermi-Hubbard system with a periodically-modulated interaction has been recently shown to resonantly absorb energy at series of drive frequencies. In the present work, with the help of static perturbation theory we argue that driving couples to Hubbard bands in a similar fashion as classical field couples to the two-level atom. The later, significantly simpler set-up described by the Rabi model is known to support resonant energy absorption at virtually the same series of driving frequencies. Our interpretation is also supported by showing that dynamics of the two-site periodically-driven Hubbard and Rabi models is formally equivalent. Relying on this insight we establish that the same Rabi-resonant behavior is displayed also by fermions confined in a harmonic trap with periodically-driven contact interactions.