Variational method and duality in the 2D square Potts model

Abstract

The ferromagnetic q-state Potts model on a square lattice is analyzed, for q>4, through an elaborate version of the operatorial variational method. In the variational approach proposed in the paper, the duality relations are exactly satisfied, involving at a more fundamental level, a duality relationship between variational parameters. Besides some exact predictions, the approach is very effective in the numerical estimates over the whole range of temperature and can be systematically improved.

20 pages, 5 EPS figures

References in corpus (6)

• Observation of FSS for a First Order Phase Transition
• Series studies of the Potts model. II: Bulk series for the square lattice
• The free energy of the Potts model: from the continuous to the first-order transition region
• 2D Potts Model Correlation Lengths: Numerical Evidence for ${\xi }_o={\xi }_d$ at ${\beta }_t$
• Large q expansion of the 2D q-states Potts model
• Ordered vs Disordered: Correlation Lengths of 2D Potts Models at β_t