On chromoelectric (super)conductivity of the Yang-Mills vacuum
  We argue that in the Copenhagen (``spaghetti'') picture of the QCD vacuum the chromomagnetic flux tubes exhibit chromoelectric superconductivity. We show that the superconducting chromoelectric currents in the tubes may be induced by the topological charge density. 
M. N. Chernodub, Jos Van Doorsselaere, Tigran Kalaydzhyan, Henri   Verschelde
hep-ph hep-lat hep-th