Non-Markovian entanglement dynamics of two spin-1/2 particles embedded in two separate spin star baths with tunable external magnetic fields
Key Laboratory of Low-Dimensional Quantum Structures and Quantum
Control, Ministry of Education, and College of Physics and
Information Science, Hunan Normal University, 410081, Changsha, P.R. China
Revised: 25 January 2010
Published online: 16 March 2010
The exact entanglement dynamics of two spin qubits in two independent spin star baths via a Heisenberg XY interaction in the thermodynamic limit has been investigated by using an operator technique. After the Holstein-Primakoff transformation, the transformed Hamiltonian is effectively equivalent to the Hamiltonian of a Jaynes-Cummings model. The results show that the dynamics of the entanglement exhibits strong non-Markovian behavior and depends on the environmental temperature, the coupling strength between the center spin and the bath, the detuning controlled by a locally applied external magnetic field, as well as the initial state of the two qubits.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010