Mimicking quantum correlation of a long-range Hamiltonian by finite-range interactions

The quantum long-range extended Ising model possesses several striking features which cannot be observed in the corresponding short-range model. We report that the pattern obtained from the entanglement between any two arbitrary sites of the long-range model can be mimicked by the model having a finite range of interactions provided the interaction strength is moderate. On the other hand, we illustrate that when the interactions are strong, the entanglement distribution in the long-range model does not match the class of a model with a few interactions. We also show that the monogamy score of entanglement is in good agreement with the behavior of pairwise entanglement. Specifically, it saturates when the entanglement in the finite-range Hamiltonian behaves similarly to the long-range model, while it decays algebraically otherwise.

Automated summary

The quantum long-range extended Ising model exhibits distinct features that are not observed in the corresponding short-range model. It has been discovered that the entanglement pattern between any two arbitrary sites of the long-range model can be mimicked by a model with finite-range interactions when the interaction strength is moderate. However, when the interactions are strong, the entanglement distribution in the long-range model does not match that of a model with only a few interactions. Furthermore, the monogamy score of entanglement is in good agreement with the behavior of pairwise entanglement.