Spontaneous electromagnetic superconductivity and superfluidity of   QCDxQED vacuum in strong magnetic field
  It was recently shown that the vacuum in the background of a strong enough magnetic field may become an electromagnetic superconductor due to interplay between strong and electromagnetic forces. The superconducting ground state of the QCDxQED sector of the vacuum is associated with magnetic-field-assisted emergence of quark-antiquark condensates which carry quantum numbers of charged rho mesons (i.e., of electrically charged vector particles made of lightest, u and d, quarks and antiquarks). Here we demonstrate that this exotic electromagnetic superconductivity of vacuum is also accompanied by even more exotic superfluidity of the neutral rho mesons. The superfluid component -- despite being electrically neutral -- turns out to be sensitive to an external electric field as the superfluid may ballistically be accelerated by a test background electric field along the magnetic-field axis. In the ground state both superconducting and superfluid components are inhomogeneous periodic functions of the transversal (with respect to the axis of the magnetic field) spatial coordinates. The superconducting part of the ground state resembles an Abrikosov ground state in a type-II superconductor: the superconducting condensate organizes itself in periodic structure which possesses the symmetry of an equilateral triangular lattice. Each elementary lattice cell contains a stringlike topological defect (superconductor vortex) in the charged rho condensates as well as three superfluid vortices and three superfluid antivortices made of the neutral rho condensate. The superposition of the superconductor and superfluid vortex lattices has a complicated "kaleidoscopic" pattern. 
M. N. Chernodub, Jos Van Doorsselaere, Henri Verschelde
hep-ph