Dynamics of pairwise entanglement in the four-qubit Heisenberg XX spin chain

Abstract

We discuss the dynamic evolution of pairwise entanglement in a four-qubit Heisenberg XX spin chain with the periodic boundary condition and the external magnetic field considered. The results show that the so-called entanglement sudden death (ESD) effect can be weakened when introducing the periodic boundary condition and the magnetic impurity. In addition, we also find that the ESD affects the dynamic evolution of entanglement between weakly interacting alternate qubits stronger than that for strongly interacting nearest qubits.

Keywords:

• pairwise entanglement
• dynamic evolution
• concurrence

Acknowledgement

We would like to acknowledge National Natural Science Foundation of China under Grant No. 10575017.