Professor Akira Furusawa and his colleagues have developed a technique that uses photon memory to freely synchronise the arrival of two photons with 25 times higher efficiency than conventional methods. In the past, photons that happened to arrive at a quantum logic gate at the same time were selected after measurement, which was a fatal problem in improving the efficiency of quantum logic gate operation. This leads to the continuous operation of quantum logic gates. The results have been published in Science Advances on 27 May (US time).
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