Flux tubes and their interaction in U(1) lattice gauge theory Original Research Article

We investigate singly and doubly charged flux tubes in U(1) lattice gauge theory. By simulating the dually transformed path integral we are able to consider large flux tube lengths, low temperatures, and multiply charged systems without loss of numerical precision. We simulate flux tubes between static sources as well as periodically closed flux tubes, calculating flux tube profiles, the total field energy and the free energy. Our main results are that the string tension in both three and four dimensions scales proportionally to the charge — which is in contrast to previous lattice results — and that in four-dimensional U(1) there is an attractive interaction between flux tubes for β approaching the phase transition.