Quantum Entanglement as a Diagnostic of Phase Transitions in Disordered   Fractional Quantum Hall Liquids
  We investigate the disorder-driven phase transition from a fractional quantum Hall state to an Anderson insulator using quantum entanglement methods. We find that the transition is signaled by a sharp increase in the sensitivity of a suitably averaged entanglement entropy with respect to disorder -- the magnitude of its disorder derivative appears to diverge in the thermodynamic limit. We also study the level statistics of the entanglement spectrum as a function of disorder. However, unlike the dramatic phase-transition signal in the entanglement entropy derivative, we find a gradual reduction of level repulsion only deep in the Anderson insulating phase. 
Zhao Liu and R. N. Bhatt
cond-mat.str-el cond-mat.dis-nn