基于轨道角动量的高维贝尔态产生OA

[Objective]Quantum communication is an emerging mode of communication with broad application prospects,com-bining with classical information science and technology.It offers unconditional security and efficient transmission of information,making it a hot research topic in today's communication field.High-dimensional quantum entanglement often exhibits strong non-locality,enhancing the security in quantum communication processes and playing a crucial role in quantum communication and computing.To meet the demand for high-dimensional entangled states in quantum information science,this paper proposes a method for generating high-dimensional Bell states based on the Orbital Angular Momentum(OAM)of photons,capable of pro-ducing the complete set of Bell state basis vectors with high fidelity.[Methods]Initially,the Spontaneous Parametric Down-Con-version(SPDC)process involving photon OAM is studied.Furthermore,a Genetic Algorithm(GA)is employed to optimize the quantum state of the pump light,aiming to obtain the required high-dimensional maximally entangled states.We analyze the char-acteristics of Laguerre-Gaussian(LG)beams in detail and explore their application in the SPDC process.By optimizing the param-eters of the pump light,maximally entangled states are generated in three-dimensional,four-dimensional,and five-dimensional spaces.[Results]A comparison of the spatial mode spectral distribution shows that the optimized entangled states possess higher fidelity to the target states.Additionally,by simulating the generation of 16 Bell states,it is verified that the produced quantum states form a complete basis for a four-dimensional Hilbert space.[Conclusion]The proposed scheme not only effectively gener-ates high-dimensional entangled states but also enables longer-distance quantum communication and potentially global quantum communication systems.Moreover,it provides new avenues for the application of high-dimensional entangled states in the fields of quantum communication and computing,significantly contributing to the advancement of quantum information science.