  A full quantum description of global vortex strings is presented in the
framework of a pure Higgs system with a broken global U(1) symmetry in 3+1D. An
explicit expression for the string creation operator is obtained, both in terms
of the Higgs field and in the dual formulation where a Kalb-Ramond
antisymmetric tensor gauge field is employed as the basic field. The quantum
string correlation function is evaluated and from this, the string energy
density is obtained. Potential application in cosmology (cosmic strings) and
condensed matter (vortices in superfluids) are discussed.
