Three-Qubit Quantum Entanglement Robustness Coupling with Kerr-like Medium

최정운

Yeen Chia Chan

Jaynes-Cummings model is widely used to represent a quantum system as it is able to explain quantum behaviour in a more accurate and simple way. To date, the study of Jaynes-Cummings model does not involve multi-photon transitions and also three-qubit quantum entanglement, both coupled with Kerr-like medium. Thus the main objective of this study is to discover new behaviour for quantum system under these two conditions coupled with Kerr-like medium. In achieving this objective, Jaynes-Cummings model is modified to include multi-photon transition and three-qubit quantum system coupling with Kerr-like medium. Under the multi-photon transition condition, Pegg-Barnett formalism is used to measure the quantum system behaviour in the modified Jaynes-Cummings model. The result shows that as the strength of the coupling increases, the quantum system behaviour becomes more active. However, as the number of photons transition increases, the influence from Kerr-like medium towards quantum system behaviour decreases. Next, under the three-qubit quantum system with one-photon transition condition, the three-qubit state interacts with Markovian and non-Markovian environments, both represented by Lorenztian spectral density. The lower bound concurrence is used to measure quantum entanglement robustness. Result shows that when Kerr-like medium coupling strength is increased for both Markovian and non-Markovian environments, the quantum entanglement are more robust. Concurrently, the influence of quantum entanglement robustness is reduced when dipole-dipole interaction is getting stronger. As a conclusion, this study discovered new quantum system behaviour under the influence of Kerr-like medium with potential application in quantum information processing.

Driss Aoune, Noureddine Benrass, Nabil Habiballah +1 more

In this work, we investigate a theoretical study of the stationary entanglement of an optomechanical system by adding a Kerr medium in the cavity where the mechanical resonator is perturbatively connected to an auxiliary qubit. The degree of entanglement between the cavity field and the mechanical system is measured by using the logarithmic negativity. We show that optomechanical entanglement is decreased by Kerr interaction due to photon blockage enhanced by mirror–qubit coupling, we also show that this enhancement is influenced by the temperature. In addition, we find that, in the presence of the mirror–qubit coupling, entanglement can arise with far weaker optomechanical coupling. The proposed scheme shows that the presence of the mirror–qubit coupling and Kerr medium is an effective control for an optomechanical system.

Hongmei Li, Xue-Mei Su

Xiao-Zhong Yuan, Ka‐Di Zhu, Zhuo-Jie Wu

Abdel‐Baset A. Mohamed, Hichem Eleuch

An analytical solution for a master equation describing the dynamics of a qubit interacting with a nonlinear Kerr-like cavity through intensity-dependent coupling is established. A superposition of squeezed coherent states is propped as the initial cavity field. The dynamics of the entangled qubit-cavity states are explored by negativity for different deformed function of the intensity-dependent coupling. We have examined the effects of the Kerr-like nonlinearity and the qubit-cavity detuning as well as the phase cavity damping on the generated entanglement. The intensity-dependent coupling increases the sensitivity of the generated entanglement to the phase-damping. The stability and the strength of the entanglement are controlled by the Kerr-like nonlinearity, the qubit-cavity detuning, and the initial cavity non-classicality. These physical parameters enhance the robustness of the qubit-cavity entanglement against the cavity phase-damping. The high initial cavity non-classicality enhances the robustness of the qubit-cavity entanglement against the phase-damping effect.