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Fast generations of tree-type three-dimensional entanglement via Lewis-Riesenfeld invariants and transitionless quantum driving

View Article: PubMed Central - PubMed

ABSTRACT

Recently, a novel three-dimensional entangled state called tree-type entanglement, which is likely to have applications for improving quantum communication security, was prepared via adiabatic passage by Song et al. Here we propose two schemes for fast generating tree-type three-dimensional entanglement among three spatially separated atoms via shortcuts to adiabatic passage. With the help of quantum Zeno dynamics, two kinds of different but equivalent methods, Lewis-Riesenfeld invariants and transitionless quantum driving, are applied to construct shortcuts to adiabatic passage. The comparisons between the two methods are discussed. The strict numerical simulations show that the tree-type three-dimensional entangled states can be fast prepared with quite high fidelities and the two schemes are both robust against the variations in the parameters, atomic spontaneous emissions and the cavity-fiber photon leakages.

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The fidelity of (a) the LRI method and (b) the TQD method for generating tree-type three-dimensional entanglement versus κ/g and γ/g, respectively. The parameters used here are same as in Fig. 5.
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f8: The fidelity of (a) the LRI method and (b) the TQD method for generating tree-type three-dimensional entanglement versus κ/g and γ/g, respectively. The parameters used here are same as in Fig. 5.

Mentions: Based on the master equation, we plot the fidelities of the LRI method and the TQD method versus and γ/g in Fig. 8. As we can see from the decrease of the fidelity of the LRI method with the increases of and γ/g in Fig. 8(a), we learn that the influence of atomic spontaneous emissions on the fidelity is greater than that of photon leakages of the cavity-fiber system. However, in Fig. 8(a) the influence of cavity-fiber photon leakages on the fidelity of the TQD method plays a full role, but that of atomic spontaneous emissions is little. As a cross reference, we can get some inspiration from Fig. 6(a). In Fig. 6(a), the highest value of the cavity-fiber excited populations (blue dashed line) of the TQD method is over 0.2 during the evolution process but that of the atomic excited populations (blue solid line) of the TQD method is near zero which caused by the detuning Δ. The highest values of the atomic excited populations (red solid line) and the cavity-fiber excited populations (red dashed line) of the LRI method are slightly higher and slightly lower than 0.05, respectively. Therefore, it is no doubt that the results of Figs 6 and 8 are corresponding to each other. Finally, it is necessary to emphasize that the fidelities of the LRI method and the TQD method are near 0.94 and over 0.955 respectively, even when . Therefore, our two schemes of the LRI method and the TQD method both are robust against the decoherence induced by the atomic spontaneous emissions and photon leakages of the cavity-fiber system.


Fast generations of tree-type three-dimensional entanglement via Lewis-Riesenfeld invariants and transitionless quantum driving
The fidelity of (a) the LRI method and (b) the TQD method for generating tree-type three-dimensional entanglement versus κ/g and γ/g, respectively. The parameters used here are same as in Fig. 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036061&req=5

f8: The fidelity of (a) the LRI method and (b) the TQD method for generating tree-type three-dimensional entanglement versus κ/g and γ/g, respectively. The parameters used here are same as in Fig. 5.
Mentions: Based on the master equation, we plot the fidelities of the LRI method and the TQD method versus and γ/g in Fig. 8. As we can see from the decrease of the fidelity of the LRI method with the increases of and γ/g in Fig. 8(a), we learn that the influence of atomic spontaneous emissions on the fidelity is greater than that of photon leakages of the cavity-fiber system. However, in Fig. 8(a) the influence of cavity-fiber photon leakages on the fidelity of the TQD method plays a full role, but that of atomic spontaneous emissions is little. As a cross reference, we can get some inspiration from Fig. 6(a). In Fig. 6(a), the highest value of the cavity-fiber excited populations (blue dashed line) of the TQD method is over 0.2 during the evolution process but that of the atomic excited populations (blue solid line) of the TQD method is near zero which caused by the detuning Δ. The highest values of the atomic excited populations (red solid line) and the cavity-fiber excited populations (red dashed line) of the LRI method are slightly higher and slightly lower than 0.05, respectively. Therefore, it is no doubt that the results of Figs 6 and 8 are corresponding to each other. Finally, it is necessary to emphasize that the fidelities of the LRI method and the TQD method are near 0.94 and over 0.955 respectively, even when . Therefore, our two schemes of the LRI method and the TQD method both are robust against the decoherence induced by the atomic spontaneous emissions and photon leakages of the cavity-fiber system.

View Article: PubMed Central - PubMed

ABSTRACT

Recently, a novel three-dimensional entangled state called tree-type entanglement, which is likely to have applications for improving quantum communication security, was prepared via adiabatic passage by Song et al. Here we propose two schemes for fast generating tree-type three-dimensional entanglement among three spatially separated atoms via shortcuts to adiabatic passage. With the help of quantum Zeno dynamics, two kinds of different but equivalent methods, Lewis-Riesenfeld invariants and transitionless quantum driving, are applied to construct shortcuts to adiabatic passage. The comparisons between the two methods are discussed. The strict numerical simulations show that the tree-type three-dimensional entangled states can be fast prepared with quite high fidelities and the two schemes are both robust against the variations in the parameters, atomic spontaneous emissions and the cavity-fiber photon leakages.

No MeSH data available.