New Universality Class in the Superconductive Phase Transition

The superconductive phase transition in the Ginzburg-Landau theory (or Coulomb-Higgs phase transition of scalar QED in 3D) is discussed in a dual formulation which focuses on the magnetic rather than the electric excitations of the system. Renormalization group analysis of the dual formulation reveals the transition to be of second order and of a new universality class. Whereas coherence length and specific heat have XY-model exponents, the magnetic penetration depth shows mean-field behavior. Experimental evidence for these predictions is discussed.