Method for processing heterodyne detection phase compensation after continuous variable quantum key distribution

Abstract

The invention discloses a method for heterodyne detection phase compensation through post processing in continuous variable quantum key distribution. The method comprises the following steps: 1) a receiving end Bob receives a quantum state prepared by a sender Alice, and partitioning data obtained through heterodyne detection into blocks according to a set proportion; 2) the Bob sends phase compensation data to the Alice; 3) according to compensation data of two neighboring phases and corresponding sending data recorded when the Alice performs quantum state preparation, the Alice calculates phase drift of an X component and phase drift of a P component of the compensation data of the two neighboring phases; 4) according to the phase drift of the compensation data of the two neighboring phases, the Alice calculates phase drift phi of the X component and phase drift theta of the P component of to-be-compensated data among the corresponding sending data recorded when quantum state preparation is executed; 5) the Alice performs phase rotation for the X component and the P component of the to-be-compensated data according to the phase drift phi and the phase drift theta, and obtains thedata subjected to phase compensation.

Description

technical field [0001] The invention relates to the technical field of quantum information, in particular to a data structure method for phase compensation of heterodyne detection by post-processing in a continuous variable quantum key distribution system. Background technique [0002] Usually, after the signal is transmitted over a long distance, especially when propagating in an atmospheric channel, the phase of the signal light will drift to a certain extent due to the influence of the channel. For the signal receiver, in order to obtain accurate information, it is necessary to perform phase compensation on the signal. In the optical fiber-based continuous variable quantum key distribution protocol, a phase reference signal is generally added when the signal is sent. By measuring the phase reference signal, a feedback voltage can be generated to the phase modulator on the eigenoptical path of the receiving end, thereby Realize real-time phase compensation. In atmospheri...

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Problems solved by technology

In atmospheric channels, however, phase compensation is more complex

[0003] Using electrical methods for phase compensation, on the one hand, the accuracy of electrical methods is limited by the accuracy of digital and analog circuits, and on the other hand, additional electrical noise will be introduced during the compensation process, so the compensation accuracy is limited

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