Quantum Phases of a Vortex String

الأصل · EN

We argue that the world-sheet dynamics of magnetic k-strings in the Higgs phase of the mass-deformed N=4 theory, is controlled by a bosonic O(3) sigma model with anisotropy and a topological theta term. The theory interpolates between a massless O(2) symmetric regime, a massive O(3) symmetric phase and another massive phase with a spontaneously broken Z₂ symmetry. The first two phases are separated by a Kosterlitz-Thouless transition. When θ= πthe O(3) symmetric phase flows to an interacting fixed point; sigma model kinks and their dyonic partners become degenerate, mirroring the behaviour of monopoles in the parent gauge theory. This leads to the identification of the kinks with monopoles confined on the string.