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تسجيل مستخدم جديدConnecting heterogeneous quantum networks by hybrid entanglement swapping
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Recent advances in quantum technologies are rapidly stimulating the building of quantum networks. With the parallel development of multiple physical platforms and different types of encodings, a challenge for present and future networks is to uphold a heterogeneous structure for full functionality and therefore support modular systems that are not necessarily compatible with one another. Central to this endeavor is the capability to distribute and interconnect optical entangled states relying on different discrete and continuous quantum variables. Here we report an entanglement swapping protocol connecting such entangled states. We generate single-photon entanglement and hybrid entanglement between particle-like and wave-like optical qubits, and then demonstrate the heralded creation of hybrid entanglement at a distance by using a specific Bell-state measurement. This ability opens up the prospect of connecting heterogeneous nodes of a network, with the promise of increased integration and novel functionalities.
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اقرأ أيضاً
Hyper-hybrid entanglement for two indistinguishable bosons has been recently proposed by Li textit{et al.} [Y. Li, M. Gessner, W. Li, and A. Smerzi, href{https://doi.org/10.1103/PhysRevLett.120.050404}{Phys. Rev. Lett. 120, 050404 (2018)}]. In the cu
rrent paper, we show that this entanglement exists for two indistinguishable fermions also. Next, we establish two {em no-go} results: no hyper-hybrid entanglement for two {em distinguishable} particles, and no unit fidelity quantum teleportation using {em indistinguishable} particles. If either of these is possible, then the {em no-signaling principle} would be violated. While several earlier works have attempted extending many results on distinguishable particles to indistinguishable ones, and vice versa, the above two no-go results establish a nontrivial separation between the two domains. Finally, we propose an efficient entanglement swapping using only two indistinguishable particles, whereas a minimum number of either three distinguishable or four indistinguishable particles is necessary for existing protocols.
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We formulate the problem of finding the optimal entanglement swapping scheme in a quantum repeater chain as a Markov decision process and present its solution for different repeaters sizes. Based on this, we are able to demonstrate that the commonly
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