Holographic Entanglement Entropy in Insulator/Superconductor Transition
  We investigate the behaviors of entanglement entropy in the holographical insulator/superconductor phase transition. We calculate the holographic entanglement entropy for two kinds of geometry configurations in a completely back-reacted gravitational background describing the insulator/superconductor phase transition. The non-monotonic behavior of the entanglement entropy is found in this system. In the belt geometry case, there exist four phases characterized by the chemical potential and belt width. 
Rong-Gen Cai, Song He, Li Li, Yun-Long Zhang
hep-th cond-mat.supr-con hep-ph