  We propose a novel mechanism for the photo-induced superconducting-like
response recently reported in cuprates and other strongly correlated materials.
This mechanism relies on quantum-fluctuating bosons consisting of electron
pairs. With periodic drive, the electron pairs and vacancies of pairs form a
coherent non-equilibrium condensate, different from conventional
superconductors, yet showing superconducting-like response in some regimes even
with dissipation. Unlike the case of driven fermionic bands which results in
the familiar Floquet bands with hybridization gaps, for driven bosons the "gap"
opens up in the momentum direction, resulting in a resonant region in momentum
space where the eigenvalues are complex. We give a simple physical argument why
this picture leads to a "perfect conductor" which exhibits superconducting-like
frequency-dependent conductivity but no Meissner response. While our model is
quite general, in the case of cuprates, quantum-fluctuating pair density wave
in the pseudogap region may serve as the origin of the quantum-fluctuating
electron pairs.
