Abstract: Quantum entanglement,as an inherent nonlocal correlation,has become one of the important available sources,and was widely applied in many fields. The quantum phase transition in strongly correlated systems,as an important phenomenon,is still a remarkable focus in condensed matter physics. In the present paper,the conception,the criteria,and the measurement of entanglement are introduced and discussed. Then,the quantum phase transitions in a representative model are investigated,and how to describe the quantum phase transitions by the quantum entanglement is also discussed. It is found that the quantum entanglement plays a key role in quantum phase transitions.

Key words: nonlocal correlation, quantum entanglement, quantum phase transitions