Quantum-information approach to rotating Bose-Einstein condensates

We investigate the two-dimensional weakly interacting rotating Bose-Einstein condensate by the tools of quantum information theory. The critical exponents of the ground-state fidelity susceptibility and the correlation length of the system are obtained for the sudden change of the ground state when the first vortex is formed. This sudden change can also be indicated by the ground state entanglement. We also find the single-particle entanglement can be an indicator of the angular momentums for some real ground states. The single-particle entanglement of fractional quantum Hall states such as Laughlin state and Pfaffian state is also studied.