Interaction potential in compact three-dimensional QED with mixed action -art. no. 105032

We use a variational wave function to calculate the energy of the interacti on between external charges in the compact Abelian gauge theory in 2+1 dime nsions with mixed action. Our variational wave functions preserve the compa ct gauge invariance of the theory both in the vacuum and in the charged sec tors. We End that a good estimate of the interaction energy is obtained onl y when we allow more variational parameters in the charged sector than in t he vacuum sector. These extra parameters are the profile of an induced elec tric field. We find that the theory has a two-phase structure: When the cha rge-2 coupling is large and negative there is no mass gap in the theory and no confinement, while otherwise a mass gap is generated dynamically and th e theory confines charges. The pure Wilson theory is in the confining phase . [S0556-2821(99)08820-7].