Quantum entanglement purification device and method

Abstract

The invention discloses a quantum entanglement purification device and method, and the device comprises a quantum entanglement building module which is used for building a quantum entanglement state between quantum memories; a local operation module which is used for enabling the electromagnetic pulses to act on the quantum memories respectively, so that the electromagnetic pulses and the quantum energy levels of the quantum memories resonate; a laser module which is used for reading excitation in the quantum memory to enable the quantum memory to emit anti-Stokes photons; local detection modules which are used for detecting anti-Stokes photons, wherein the quantum memories are in one-to-one correspondence with the local detection modules; and a central control module which is used for judging whether quantum entanglement purification is successful or not according to a detection result of the local detection module, and controlling the quantum entanglement establishment module, the local operation module, the laser module and the local detection module to repeatedly perform quantum entanglement purification under the condition that the quantum entanglement purification is not successful. According to the device and the method, the fidelity of the initial quantum entanglement state is not limited, and the high-fidelity quantum entanglement state can be realized by controlling the implementation times of quantum entanglement purification.

Description

technical field [0001] The present disclosure relates to the field of quantum information communication, in particular to a quantum entanglement purification device and method. Background technique [0002] Quantum communication can realize unconditional secure communication based on physical principles. However, since the loss of photons in optical fibers increases exponentially with the increase of transmission distance, direct transmission of single photons cannot achieve quantum communication longer than 500 kilometers. A communication scheme based on quantum relay can effectively solve this problem. Duan Luming and others proposed a quantum relay scheme (DLCZ scheme) based on single photon entanglement between atomic ensembles in 2001. The advantage of this scheme is that it is not sensitive to the loss of photons, which is conducive to the realization of long-distance quantum entanglement. This scheme has a wide range of applications in many physical systems, and has ...

AI Technical Summary

Problems solved by technology

[0010]Aiming at the above technical problems, this disclosure proposes a quantum entanglement purification device and method to solve quantum entanglement caused by unsatisfactory actual conditions in the prior art state fidelity problem

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