  The folding transition of single, long semiflexible polymers was studied with
special emphasis on the chain length effect using Monte Carlo simulations.
While a relatively short chain (10-25 Kuhn segments) undergoes a large discrete
transiton between swollen coil and compact toroid conformations, a long chain
(50 Kuhn segments) exhibits an intrachain segregated state between the
disordered coil and ordered toroid.
