  Twisted bilayer systems with discrete magic angles, such as twisted bilayer
graphene featuring moir\'{e} superlattices, provide a versatile platform for
exploring novel physical properties. Here, we discover a class of superflat
bands in general twisted bilayer systems beyond the low-energy physics of
magic-angle twisted counterparts. By considering continuous lattice
dislocation, we obtain intrinsic localized states, which are spectrally
isolated at lowest and highest energies and spatially centered around the AA
stacked region, governed by the macroscopic effective energy potential well.
Such localized states exhibit negligible inter-cell coupling and support the
formation of superflat bands in a wide and continuous parameter space, which
can be mimicked using a twisted bilayer nanophotonic system. Our finding
suggests that general twisted bilayer systems can realize continuously tunable
superflat bands and the corresponding localized states for various photonic,
phononic and mechanical waves.
