Entanglement control in two interacting asymmetric qubits coupled off-resonance to a radiation field*

In previous works [1,2], we have studied the manipulation of entanglement sudden death (ESD) and asymptotic behavior in a system of two interacting identical atoms (qubits) coupled to radiation field. We showed how the interplay among the different system parameters can be used to tune the system dynamics and asymptotic behavior. In this work, we study a system of two interacting asymmetric atoms coupled to a radiation field at non-zero detuning. The two atoms are coupled through dipole-dipole and Ising interactions. We provide an exact analytic solution for the system dynamics that span the entire system parameter phase space starting from any initial state. We show how the asymmetry of the system can be utilized to avoid ESD and enhance its entanglement asymptotic value, when tuned with the other system parameters such as the non-zero detuning, and dipole-dipole and Ising couplings. This system can be realized in quantum dots (or Rydberg atoms) in optical cavities and superconducting (or hybrid) qubits in linear resonators, which is of special interest in the field of quantum information processing (QIP).

[1] Gehad Sadiek, Wiam Al-Drees and Sebawe Abdullah, Optics Express 27, 33799 (2019).

[2] Gehad Sadiek, Wiam Al-Drees, Salwa Shaglel and Hala Elhag, Entropy 23, 00629 (2021).