Topological order and magnetic flux fractionalization in Josephson   junction ladders with Mobius boundary conditions: a twisted CFT description
  We propose a CFT description for a closed one-dimensional fully frustrated ladder of quantum Josephson junctions with Mobius boundary conditions (see cond-mat/0503555; we show how such a system can develop topological order thanks to flux fractionalization. Such a property is crucial for its implementation as a "protected" solid state qubit. 
Gerardo Cristofano, Vincenzo Marotta, Adele Naddeo, Giuliano Niccoli