End-to-end entanglement in a polar-molecule array under intrinsic decoherence

Dynamic entanglement between two end molecules in a polar-molecule array is investigated in static electric fields. Specific initial states are set to probe the evolution of the molecular system under the influence of intrinsic decoherence. We analyze the degree of entanglement between the end molecules by use of concurrence. When the Bell states are initially shared between the end molecules, the end-to-end concurrence shows either a fragile or a robust behavior. The robust concurrence is less affected by decoherence, reflecting a situation that the initial Bell state can be shared between the end molecules for long periods of time. The stability of the entanglement shared between two arbitrary molecules in the array is further studied. Furthermore, we show how to induce a high end-to-end concurrence via transfer of a separable state. The state is transferred from one end molecule to the other. During the back-and-forth transfer processes, the concurrence cyclically reveals high peaks, corresponding to different Bell-like states. In addition, population inversion is observed to only occur at the end molecules in the array. We further examine the contribution of effective states to the concurrence and discuss the effects of decoherence, dipole-field interaction, and dipole-dipole interaction on its properties.

Automated summary

In this study, the dynamic entanglement between two molecules in a polar-molecule array under static electric fields is investigated. The research focuses on the evolution of entanglement under the influence of intrinsic decoherence, the stability of entanglement between arbitrary molecules in the array, and the induction of high end-to-end concurrence through state transfer. The study demonstrates the fragile and robust behavior of entanglement under different initial states, and reveals the cyclic peaks of concurrence corresponding to different Bell-like states during the state transfer processes.