Hybrid Defect Phase Transition

Miron Kaufman

For the q-state Potts model with 2 < q <= 4 on the square lattice with a defect line, the order parameter on the defect line jumps discontinuously from zero to a nonzero value while the defect energy varies continuously with the temperature at the critical temperature. Monte Carlo simulations (Diep, Kaufman, Phys Rev E 2009) confirm a renormalization group (hierarchical lattice) prediction (Kaufman, Griffiths, Phys Rev B 1982).