The Topological Nature of RV − RI Phase Transition in N-Paraffins

The (Formula presented.) 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.