The world's first seawater quantum communication experiment was successful
Recently, Shanghai Jiao Tong University Kim Hyon Min team successfully conducted the first seawater quantum communication experiment, observing the photon polarization quantum state and quantum entanglement can maintain the quantum properties in seawater, the first time in the international experiment verified the feasibility of underwater quantum communication , An important step toward establishing a network of underwater and air-sea mass communications in the future. At present, quantum communication based on optical fiber and free-space atmospheric channels has proved feasible. So, the ocean can be used as a quantum channel it? Kim Hyun Min said that although the effects of scattering and loss of photons in seawater, such as suspended matter and salinity in seawater, are much greater than those in optical fiber and the atmosphere, seawater actually has a blue-green window with a lower loss during photon transmission Can be detected by commercial single-photon detectors. Therefore, seawater-based quantum communication is theoretically feasible. "And, without a sea, a globalized quantum communication network is incomplete." In their latest experiment, they chose the polarization of photons as a carrier for information encoding and demonstrated by simulations that under very large losses and scattering, the polarimetric encoded photons would only be lost without the quantum bit flipping. That is to say, even after experiencing a huge channel loss of seawater, a small number of single photons can still be used to establish a security key even if it survives. The current results show that underwater quantum communication up to several hundred meters, although the channel is short, but the underwater one hundred meters submarine and sensor network nodes and other secure communications, even from a few meters deep underwater Secrecy of satellites and aircraft to communicate is also a step closer to the "closed area" of seawater than previously thought, and therefore "can show its talents" in the military and other fields. Kim Hyo-min pointed out that although it is only the first step towards underwater quantum communication, there is still a long way to go from practical underwater and air-sea integrated quantum communication links and networks. However, "the latest research proves that the realization of quantum communication technology , Into the land, the future of the sea can be expected. " Changxing Mingwang Rubber & Plastic Technologies Co.,Ltd. , https://www.cxmingwang.com