Knots are Generic Stable Phases in Semiflexible Polymers

Semiflexible polymer models are widely used as a paradigm to understand structural phases in biomolecules including folding of proteins. Since stable knots not so common real proteins, the existence semiflexible polymers has been explored much. Here, via extensive replica exchange Monte Carlo simulation, we investigate same for bead-stick and bead-spring homopolymer model that covers whole range from flexible stiff. We establish fact presence phase diagram is dependent on ratio rb/rmin where rb equilibrium bond length rmin distance strongest nonbonded contacts. Our results provide evidence both if outside small window around unity, then depending bending stiffness, one always encounters knotted along with usual frozen bent-like structures at low temperatures. These findings prompt us conclude generic polymers.