Field Theory of Superconductor and Charged Vortex

A Lagrangian of a Schrödinger type complex scalar field of Cooper pair, a U(1) gauge field of electromagnetism, and a neutral scalar field of acoustic phonon with constant background charge density is proposed for an effective field theory of conventional superconductivity. We find static charged vortex solutions of finite energy and, for the critical couplings of the quartic self-interaction coupling of complex scalar field and the cubic Yukawa type coupling between neutral and complex scalar field, these charged vortices saturate the BPS (Bogomolny-Prasad-Sommerfield) bound, that guarantees the nonperturbative classification of type I and II superconductors.