  We show that a nonlinear metallo-dielectric layered slab of subwavelength
thickness and very small average dielectric permittivity displays optical
multistable behavior at arbitrary low optical intensities. This is due to the
fact that, in the presence of the small linear permittivity, one of the
multiple electromagnetic slab states exists no matter how small is the
transmitted optical intensity. We prove that multiple states at ultra-low
optical intensities can be reached only by simultaneously operating on the
incident optical intensity and incidence angle. By performing full wave
simulations, we prove that the predicted phenomenology is feasible and very
robust.
