Binary iterative clock synchronization system and method based on polarization entanglement GHZ states

Abstract

The invention provides a binary iterative clock synchronization system based on polarization entanglement GHZ states, which comprises a first synchronization party, a second synchronization party anda transmission party. The first synchronization party is connected with the second synchronization party by a classical channel, the transmission party is connected with the first synchronization party by a quantum channel, and the transmission party is connected with the classical channel by the quantum channel, wherein the transmission party implements preparation of polarization entanglement GHZ states of three photons and carries out measurement on a polarization state of one photons; and the first synchronization party and the second synchronization party execute measurement on polarization states of the other two photons, and measurement results of the second synchronization party and the transmission party are compared to acquire measurement sequence information between the first synchronization party and the second synchronization party. Transmission of an optical signal is unidirectional transmission, and the binary iterative clock synchronization system has no requirement fora transmission rate of the signal in each direction, has fewer limitations and has fewer influences generated by optical fiber unstable factors in the transmission process.

Description

technical field [0001] The invention relates to the technical fields of quantum information and optical communication, in particular to a dichotomous iterative clock synchronization system and method based on polarization-entangled GHZ states. Background technique [0002] High-precision clock synchronization plays an important role in many applications such as basic scientific research, information security, communication, navigation, and homeland security. With the continuous development of modern atomic clock technology, the accuracy of the clock has reached 10 -18 s. In contrast, the accuracy of clock synchronization technology is only 10 -9 s, nowhere near the accuracy of the clock itself. In precision time applications, the resolution and accuracy of clock synchronization techniques become the major limiting factors. Therefore, the research on improving the precision of clock synchronization technology has attracted more and more attention of researchers. [0003]...

AI Technical Summary

Problems solved by technology

However, in this solution, the optical signal is also transmitted bidirectionally, and it is necessary to ensure that the signal transmission speed in each direction is the same, which limits its practicability to a certain extent.

[0008] In the existing technology, for example, the patent 201611081905.1 tries to use the optical fiber time synchronization method to obtain the time signal at the receiving end with the advantage of high accuracy, and accurately realize time synchronization, but it is difficult to break through the shot noise limit

[0009] However, in the existing technology, such as patent 201810436641.X, trying to use the frequency entangled light source as the carrier of the time signal, so as to break through the shot noise limit, but using bidirectional transmission, it is inevitable that the propagation speed of the optical signal along the optical fiber in different directions have high demands

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