  Chirality-induced spin selectivity is a spin-splitting phenomenon from a
helical structure with a considerably effective spin-orbit coupling. This
unexpectedly large spin-splitting phenomenon has been experimentally observed
in chiral organic molecules, which typically show a weak spin-orbit coupling.
To understand this, we use the renormalized mean-field theory and
Landauer-B\"{u}ttiker formulas to study the transport properties of
single-stranded DNA in the presence of strong electron correlation. It shows a
significant spin polarization of 46.5% near the Coulomb repulsion limit, which
explains the extremely high spin polarization observed in experiments. Compared
to systems without electron correlation, the averaged spin polarization in this
case is 2 to 4 times greater across various system sizes. Furthermore, the
parameter dependence of the spin polarization and the underlying
Metal-Insulator transition are studied.
