Entanglement as a quantum order parameter

  title={Entanglement as a quantum order parameter},
  author={Fernando G. S. L. Brand{\~a}o},
  journal={arXiv: Quantum Physics},
  • F. Brandão
  • Published 7 September 2005
  • Physics
  • arXiv: Quantum Physics
We show that the quantum order parameters (QOP) associated with the transitions between a normal conductor and a superconductor in the BCS and eta-pairing models and between a Mott-insulator and a superfluid in the Bose-Hubbard model are directly related to the amount of entanglement existent in the ground state of each system. This gives a physical meaningful interpretation to these QOP, which shows the intrinsically quantum nature of the phase transitions considered. 
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