Holographic Superconductors with Various Condensates
  We extend earlier treatments of holographic superconductors by studying cases where operators of different dimension condense in both 2+1 and 3+1 superconductors. We also compute a correlation length. We find surprising regularities in quantities such as $\omega_g/T_c$ where $\omega_g$ is the gap in the frequency dependent conductivity. In special cases, new bound states arise corresponding to vector normal modes of the dual near-extremal black holes. 
Gary T. Horowitz and Matthew M. Roberts