The Topological Nature of R V − R I Phase Transition in N‐Paraffins

The phase transition is investigated in rotator phase systems using the XY model on an orthohexagonal lattice. In contrast to the first‐order behavior induced by coupling with the Herringbone order parameter amplitude, it is showed that, in its absence, the transition is second‐order and mediated by BKT vortices. Employing low‐ and high‐temperature expansions, Villain duality, and simulations on an honeycomb lattice, a close agreement between theory and numerics is found. The BKT transition temperature obtained from analytics matches simulation results within 13%, confirming the universality of this topological transition.