The concepts of concurrence, 3-steerability, and Clauser–Horne–Shimony–Holt (CHSH) inequality are employed to investigate the environmental impacts on the quantum correlations of the two-spin-1/2 Heisenberg XYZ chain model. In particular, the effects of a homogeneous magnetic field, symmetric cross interaction, and dipole–dipole interaction on the entanglement, degree of steerability, and non-locality are discussed. Results show that the entanglement and steering phenomena are bounded by the non-locality for both positive and negative values of dipole–dipole coupling. It has also been observed that higher symmetric cross-interaction strengthens the quantum correlations, whereas the homogeneous magnetic field weakens the quantumness of the system. The findings indicate that a magnetic field normal to the magnetic dipole yields better quantum correlations than when they are parallel.
1 December 2022 in Optical and Quantum Electronics
The possibility of generating of some quantum correlations of the entangled or separable initial two-qubit system interacting with a deformed cavity mode in the presence of dipole-dipole interaction is discussed. These quantum correlations are the coherence, non-separability and steering degrees which are quantifiers by using $$ l_1 $$ norm of coherence, Entanglement of Formation and Einstein–Podolsky–Rosen -steering. It is shown that maximizing or minimizing the quantum correlations depends on the initial setting states of the two-qubit system. To maximize the quantum correlations on the presence of deformation, one has to prepare the initial two-qubit system in an entangled state, setting large values of the coupling dipole and decreasing the effect of the deformation parameter.
This paper investigates quantum correlations between two identical spin-1/2 particles linked by long-range dipolar interactions. A time-dependent symmetric cross-spin interaction and an external homogeneous magnetic field that varies with time are also applied to the system. Quantum correlations, such as entanglement, steering, and steered quantum coherence, are quantified using concurrence, three-steering functions, and the l1 norm measure of coherence, respectively. These quantum correlations are examined based on the direction of interaction for dipole–dipole interactions along either the x-axis or z-axis and are symmetric concerning Zeeman energy along these axes. The maximal bounds of all three quantifiers are obtained by increasing the frequency of the time-dependent and symmetric coupling parameters. These maximal bounds significantly strengthen when considering symmetric and Zeeman interactions along the x-axis; however, the pinnacle of entanglement is reached in perpendicular configurations.
24 June 2024 in International Journal of Structural Stability and Dynamics
This paper examines the dynamics of a W-configuration four-level atom in a quantized cavity field and the system driven by an external classical field. By applying some canonical transformations, we derive analytical solutions to the Schrdinger equation for the corresponding Hamiltonian. The effects of the external field parameters and detuning on the relative entropy of coherence, Wigner function, and Pancharatnam phase of the system are then analyzed. It is found that the external field parameter has a significant effect on the coherence of the system, while the detuning parameters may increase the maximum bounds of the coherence. In addition, the Wigner function is utilized to quantify the quantumness and classicality of the system in phase space. It is observed that the external field has a greater effect on the classicality of the system than the detuning parameters. Furthermore, the dynamics of the Pancharatnam phase displays rapid oscillations for large detuning values, whereas the external field diminishes the number of phase jumps.