Floquet-Induced Superfluidity with Periodically Modulated Interactions of Two-Species Hardcore Bosons in a One-dimensional Optical Lattice

We consider two species of hard-core bosons in a one-dimensional optical lattice with periodically modulated repulsive interactions. Using Floquet theory the periodic can be mapped to an effective Hamiltonian for high frequencies, which is described by a static interaction and hopping parameters that depend on the local densities. In particular, if the density difference of one species is non-zero on neighboring sites, the effective hopping of the other species is reduced and can even take on negative values. Using a combination of analytic calculations and different numerical simulations we establish the full quantum phase diagram for half-integer filling for this system. The density-dependent reduction of hopping drives a quantum phase transition into a superfluid phase. For negative hopping a previously unknown state is found, where one species induces a gauge phase of the other species, which leads to a new superfluid phase. The corresponding experimental signatures in time-of-flight experiments are calculated and show characteristic signatures of the different phases.