Entanglement swapping theory and beyond

Abstract

We consider entanglement swapping schemes for maximally entangled states, each of which is realized by Bell measurements. The entangled states considered include bipartite maximally entangled states, d-level Bell states and Greenberger-Horne-Zeilinger states. We also consider the entanglement swapping chains proposed by Hardy et al. [Phys. Rev. A. 62(5) 052315] for maximally entangled states. Applications of the proposed entanglement swapping schemes in quantum cryptography are described.

Quantum memory assisted entropic uncertainty and entanglement dynamics: Two qubits coupled with local fields and Ornstein Uhlenbeck noise

“…Even though quantum physics makes it difficult to forecast which set of measurements will be observed, it is feasible to combine two particles into a single quantum state so that when one is detected as spin-up, the other is always detected as spin-down, and vice versa. Quantum entanglement has been utilized in experiments to establish quantum teleportation [16], and it has potential applications in quantum computing [17], quantum cryptography [18], communications [19], quantum radar [20] and entanglement swapping [21].…”

“…In this case, we want to discuss the dynamical map of a Werner type mixed entangled state and the relationship between entanglement and entropic uncertainty and its regulation. This is significant because the dynamics of open quantum systems are crucial for the development of quantum protocols and the inter-transmission of information between two locations [21]. The main source of uncertainty is that quantum systems cannot be completely isolated from their external mediums, which can accommodate a variety of disorders [22][23][24][25].…”

Security proof for qudit-system-based quantum cryptography against entanglement-measurement attack

“…To solve this problem, we provide the security proof in this paper. We will provide the proof by taking d-level n-particle GHZ states [18] as an example.…”