Generation system and method for spinning-orbital angular momentum hybrid entangled state

Abstract

The invention discloses a generation system and a generation method for a spinning-orbital angular momentum hybrid entangled state. The system consists of a single photon source, a spinning-orbital angular momentum conversion unit, a spinning-orbital angular momentum hybrid entangled state separation unit and a feedback compensation unit, wherein the spinning-orbital angular momentum hybrid entangled state separation unit obtains spinning-orbital angular momentum hybrid entangled state photons through a polarization beam splitter, a polarization controller and a Q-plate phase plate; the separation unit realizes separation of horizontal polarization single photons from the spinning-orbital angular momentum hybrid entangled state photons through two beam splitters, two full reflectors and two dove prisms; the feedback compensation unit feeds back and transmits non-converted horizontal polarization light to the spinning-orbital angular momentum conversion unit for further conversion. The generation system disclosed by the invention realizes high-efficiency conversion of a high-purity spinning-orbital angular momentum hybrid entangled state, so that the system cost and the communication error rate are reduced, and the security of the system is enhanced.

Description

technical field [0001] The invention belongs to the field of optical communication and quantum information, and in particular relates to a system and method for generating a spin-orbit angular momentum mixed entanglement state. Background technique [0002] As early as 1909, people realized that photons can carry spin angular momentum, and the spin angular momentum is related to the circular polarization state of the photon. The eigenstates of the operators carry Therefore, a two-dimensional Hilbert space can be constructed by using the spin angular momentum of photons, and information can be encoded in this two-dimensional space. However, it was not until 1992 that Allen's team at Leiden University in the Netherlands proved for the first time that photons can carry another form of angular momentum—photon orbital angular momentum. Research has shown that each single photon contains a definite orbital angular momentum Among them, l is the characteristic quantum number o...

AI Technical Summary

Problems solved by technology

On the one hand, due to the constraints of the material properties of the device, the conversion efficiency of the mixed entangled state is not very high; Two kinds of angular momentum states with different properties exist at the same time. In order to make full use of the high-dimensional quantum entanglement properties of the spin-orbit angular momentum mixed entangled state, it is necessary to find a way to separate the two to obtain a high-purity spin-orbit angular momentum mixture. Entangled state

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