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Two Driven Coupled Qubits in a Time Varying Magnetic Field: Exact and Approximate Solutions |
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PP: 1071-1084 |
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Author(s) |
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E. I. Lashin,
Gehad Sadiek,
M. Sebawe Abdalla,
Elham Aldufeery,
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Abstract |
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We study the dynamics of a two-qubit system coupled through time dependent anisotropic XYZ Heisenberg interaction
in presence of a time varying non-uniform external magnetic field. Exact results are presented for the time evolution of the system
under certain integrability conditions. Furthermore, the corresponding entanglement of the system is studied for different values of
the involved parameters. We found that the time evolution and different properties of entanglement such as amplitude, frequency and
profile can be finely tuned by the interplay of the characteristics of the time-dependent magnetic field and exchange coupling. Also we
show how the discrete symmetries of the system Hamiltonian, which splits its Hilbert space into two distinct subspaces, can be utilized
to deduce the dynamics in one of its two distinct subspaces from the other one. Moreover, approximate results for the time evolution
are provided utilizing the rotating wave as well as the perturbation approximations for the special case of either static magnetic field
or exchange coupling. We compare the range of validity of the two approximation methods and their effectiveness in treating the
considered system and determine their critical parameters. |
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