Genuine tripartite nonlocality and entanglement in curved spacetime

We study the genuine tripartite nonlocality (GTN) and the genuine tripartite entanglement (GTE) of Dirac fields in the background of a Schwarzschild black hole. We find that the Hawking radiation degrades both the physically accessible GTN and the physically accessible GTE. The former suffers from “sudden death” at some critical Hawking temperature, and the latter approaches to the nonzero asymptotic value in the limit of infinite Hawking temperature. We also find that the Hawking effect cannot generate the physically inaccessible GTN, but can generate the physically inaccessible GTE for fermion fields in curved spacetime. These results show that on the one hand the GTN cannot pass through the event horizon of black hole, but the GTE do can, and on the other hand the surviving physically accessible GTE and the generated physically inaccessible GTE for fermions in curved spacetime are all not nonlocal. Some monogamy relations between the physically accessible GTE and the physically inaccessible GTE are found.

Product-form monogamy relations of entanglement in multiqubit systems

Monogamy relations of entanglement play an important role in quantum systems, however, most of them are given in summation form. In this paper, we investigate the product-form monogamy relations of multipartite entanglement in terms of the [Formula: see text]th power of concurrence and negativity. Compared with the existing monogamy relations, the product-form monogamy relations of multi-body quantum entanglement have a stricter lower bound.