  A theoretical model is presented to compute the electronic band structures
and optical absorption spectra for twisted incommensurate few-layers graphene
(tLFG) systems of arbitrary architecture. This is accomplished using an
integrated virtual crystal approximation and tight-binding (VCA-TB) method,
where the VCA is achieved by a mathematical averaging formalism developed over
the quasi-infinite ensemble of interlayer bond configurations. The results show
that the low-energy electronic band structures of the incommensurate tLFG
systems of N graphene layers are formed of N overlapping Dirac cones centered
on the K-points of the Brillouin zones of the graphene layers. This yields
effective gaps between the saddle points of the valence and conduction bands of
these tFLG systems, that are tunable with the incommensurate twist angles. The
optical absorption spectra are also calculated for these systems; in
particular, they display clear spectral peaks which correspond to the
accessible electronic transitions across the gaps between the valence and
conduction bands. The optical absorption results highlight the potential of
these incommensurate tFLG systems for applications in graphene based tandem
cells.
