Module of helicity, quantum fluctuations and transformation in superconducting state of Josephson contacts

Influence of quantum fluctuations on phase transition in two-dimensional Josephson contacts in the framework of 2D XY-model has been studied. In the self-consistent harmonic approximation the system linear response to its perturbation by the phase homogeneous gradient (module of spirality) is calculated as a function of dimensionless temperature and quantum parameter a determined by final capacity of each contact. Calculation of the value permitted ascertaining the temperature dependence of the Kosterlitz-Thouless transition on q, which in a wide range of q values agrees well with the results of numerical simulation by the Monte Carlo quantum method