The Effect of Field Changing on Two Qubit Entanglement with Different Criteria

M. Mirzaee and M. Batavani Department of Physics, Faculty of Science, Arak University, Arak 38156-8-8349, Iran

Received: February 9, 2014; Revised version: December 14, 2014; In final form: December 17, 2014

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We investigate the effect of field changing on two qubit entanglement. We choose the coherent state, the cat state and the squeezed state as different states of interacting field with atom. The correlation between two qubits can be degraded by environmental noise, this phenomenon has been labelled sudden death of entanglement. The double Jaynes-Cummings model as a solvable model is used for describing the dynamic of sudden death of entanglement. We measure two-qubit entanglement using the concurrence and the negativity. The Fisher information is introduced, too, and compares results with previous entanglement measures. Finally we conclude that the Fisher information is not an entanglement measure.

DOI: 10.12693/APhysPolA.127.663 PACS numbers: 03.65.Ud