The relationship between a topological Yang-Mills field and a magnetic   monopole
  We show that a Jackiw-Nohl-Rebbi solution, as the most general two-instanton, generates a circular loop of magnetic monopole in four-dimensional Euclidean SU(2) Yang-Mills theory. 
Nobuyuki Fukui, Kei-Ichi Kondo, Akihiro Shibata and Toru Shinohara
hep-th