The influence of dipole-dipole interaction and initial coherence of two flux qubits interacting with two different electronic superconducting LC-cavities in thermal states on the entanglement degree has been investigated.
We have investigated the entanglement between two dipole coupled two-level artificial atoms (superconducting qubits, ion, spins etc.). The model, in which only one atom is trapped in an lossless cavity and interacts with single-mode thermal field, and the other one can be spatially moved freely outside the cavity has been carried out. We have considered the effect of the atomic coherence on the entanglement behavior. We have shown that a thermal field might cause high entanglement between the atoms both for coherent and incoherent initial atomic states only for small values of cavity mean photon number. We have also derived that the degree of entanglement is weakly dependent on the strength of dipole-dipole interaction for coherent initial states. In the considered model the atoms would get entangled even when both atoms are initially in the excited state.
The entanglement of two dipole-coupled superconducting flux qubits with degenerate and nondegenerate twophoton transitions interacting with one-mode or two-mode field in lossless cavity has been investigated. The influence of dipole-dipole interaction on the entanglement between two qubits for different initial atom-field entangled states has been considered. The results show that the entanglement between two artificial atoms can be increased by means of dipole-dipole interaction and for some initial states the entanglement sudden death effect can be weakened.
We have investigated the influence of dipole-dipole interaction and initial atomic coherence on atomic entanglement dynamics of two qubits. We have considered a model, in which only one atom couples to a quantum electromagnetic field in a cavity, since one of them can move around the cavity. We have shown that the entanglement arises for all pure atomic state even when both atoms are initially in the excited states. We have also derived that degree of entanglement is enhanced in the presence of the atomic coherence.
We have investigated the influence of dipole-dipole interaction and initial atomic coherence on atomic entanglement dynamics of two qubits. We have considered a model, in which only one atom couples to a quantum electromagnetic field in a cavity, since one of them can move around the cavity. We have shown that the entanglement arises for all pure atomic state even when both atoms are initially in the excited states. We have also derived that degree of entanglement is enhanced in the presence of the atomic coherence.