任意多体高维偏振纠缠态的有效制备
摘要
Quantum entanglement plays a crucial role in the area of quantum information processing, which was widely used in various quantum information tasks. With the development of quantum information, more and more attentions are paid to high dimensional quantum state and entangled state, since higher dimension means stronger nonlocality, which enables securer and more powerful quantum information processing. Thereafter, how to create entangled qudits efficiently is worth discussed, which is the motivation of this paper. Based on the technique of cross phase modulation, we firstly introduce a single-photon qudit (<italic>n</italic>-dimension) encoded by spatial mode as ancilla, and then let it interact with n pairs of Bell states in the Kerr medias respectively. Finally, the arbitrary two-partite polarized entangled qudits could be generated after the multi-photon interference. This approach could be directly generalized to the generaion of arbitrary multi-partite polarized entangled qudits. The interactions between an ancilla single-photon qudit and n multi-photon GHZ states, associated with multi-photon interference, will yield the desired arbitrary multi-partite polarized entangled qudits. Except of the inevitable multi-photon interference, which is used to generate polarized qudit from single photons, all the generation processes are deterministic, therefore the generation efficiency is higher than the former proposals. In addition, using quantum nondemolition detection module to preserve two cases that all the single photons appear in the same spatial mode, the success probability of multi-photon interference, i.e., the generation of entangled qudits could be increased. Furthermore, the generated multi-partite polarized entangled qudits are flexible, whose coefficients could be adjusted flexibly by the single-photon unitary operations used in the generation of single-photon qudit. Thanks to this flexibility, it is convenient for the research of the property of entangl