Quasi-probability information in a coupled two-qubit system interacting non-linearly with a coherent cavity under intrinsic decoherence

Abdel-Baset A Mohamed,Hichem Eleuch

doi:10.1038/s41598-020-70209-5

Abstract

We explore the phase space quantum effects, quantum coherence and non-classicality, for two coupled identical qubits with intrinsic decoherence. The two qubits are in a nonlinear interaction with a quantum field via an intensity-dependent coupling. We investigate the non-classicality via the Wigner functions. We also study the phase space information and the quantum coherence via the Q-function, Wehrl density, and Wehrl entropy. It is found that the robustness of the non-classicality for the superposition of coherent states, is highly sensitive to the coupling constants. The phase space quantum information and the matter-light quantum coherence can be controlled by the two-qubit coupling, initial cavity-field and the intrinsic decoherence.

Highlights

We explore the phase space quantum effects, quantum coherence and non-classicality, for two coupled identical qubits with intrinsic decoherence
Motivated by the important role of the phase space quantum effects, intrinsic decoherence and coherent fields in the quantum information, we introduce analytical solutions for the intrinsic decoherence model of two coupled qubits nonlinearly interacting with a coherent cavity-field
We focus on the case where the initial state of the two qubits is ρQs (0) = |e1e2 e1e2|, and the cavity is considered initially in a superposition of coherent states

Summary

Wigner distribution

The phase space quasi-probability distributions (QPDs) are the measure of the non-classicality for the state ρ(t) , which are defined b y47,48: F(β, s). By increasing the coupling J or the intrinsic decoherence the distinction between the classical and the quantum behaviors of the Wigner function become more noticeable. The coupling rate of the two-qubit interaction leads to smoothing and reduction of the WD oscillations It disappears completely in the presence of the intrinsic decoherence. We observe that the amplitudes, the regularity and the stability of the generated mixedness can be affected by the initial coherent field intensity

Conclusion

Additional information