The hottest new technology of quantum radar in Chi

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China tests new technology of quantum radar

it is reported that Chinese researchers have conducted an experiment that may expand the detection range of quantum radar for stealth aircraft. In a paper published earlier this month in the "physics review communication", a research team from the University of science and technology of China in Hefei, Anhui Province, described their experiment in detail. The experiment showed for the first time that the weak value measurement method, a new quantum measurement technology, can detect signals that could not be detected before

it is reported that this technology uses a very "gentle" method to repeatedly measure the quantum state of subatomic particles, which may be particularly effective for the detection of extremely weak signals, such as the radar characteristics of stealth aircraft

a quantum scientist at Nanjing University in Jiangsu Province who did not participate in the study reminded that this was "a laboratory achievement, which is not mature and cannot be immediately put into field use". However, the quantum scientist said that this study may "expand the detection range of quantum radar". Quantum scientists at the University of science and technology of China have produced the world's first quantum satellite, which was successfully launched in August this year, and has also created the world's longest distance terrestrial quantum communication network

it is reported that according to the information of China Electronics Technology Corporation, researchers from the University of science and technology of China also participated in the development of China's first quantum radar system. Earlier this year, China Electronics Technology Corporation announced that the effective detection range of China's quantum radar technology reached 100 kilometers, which is five times that of the paper packaging industry, which relies more on stabilizing domestic demand and overseas quantum radar prototypes

China believes that the stealth aircraft of the United States and its allies pose a major threat to China's regional interests. Japan received its first F-35 stealth fighter last month. In the future, China is likely to be surrounded by more stealth fighters and bombers

it is reported that the quantum radar system produces pairs of entangled optical particles, namely photons. One photon in the photon pair is emitted, and the other is left at the radar station. After the target position is locked, some photons will be reflected back. By realizing the company's development strategic goal and matching with the entangled photons retained in the radar station, it can be confirmed that they are photons' identity. By measuring the reflected photons, researchers can calculate the physical properties of the target, such as size, shape, speed and attack angle. However, a major problem of quantum radar is that the number of photons reflected is small, and the larger the distance from the target, the smaller the number of photons reflected. The theoretical limit distance is called the shot noise limit. If it is exceeded, the target cannot be detected even under the best observation conditions

it is reported that in addition to the problem of the limit of shot noise, the information carried by photons may also be covered up by the subatomic noise generated between photons, and the detection device cannot make reliable measurements, because photons hit the detection device like random projectiles, which is the name of the so-called shot. Led by Professor Guo guangcan and Professor Li Chuanfeng, the research team of the University of science and technology of China (2) food producers purchasing food related products announced that they have broken through the limit of shot noise using high-precision quantum weak measurement technology, and can achieve accurate detection even when the number of photons is very small

it is reported that this technology originates from a paradox in quantum physics. In the subatomic world, measurement means destruction. The measurement of subatomic particles will inevitably destroy its initial quantum state. But in the 1980s, scientists finally found a solution. The weak measurement method will not cause the collapse of the quantum state. Although each weak measurement can only obtain a small amount of information, repeated measurements of the same particles can obtain robust statistics about attributes, that is, correct guesses. However, the early weak measurement scheme is inefficient. Only a small proportion of photons within the detection distance can be measured, and the rest of photons are discarded

it is reported that in recent years, scientists have developed a new method called energy cycle measurement, which circulates photons in a special device, so as to reduce the number of discarded photons. The research team of the University of science and technology of China has carried out a laser beam deflection measurement test, which proves that this method can break through the limit of shot noise. They said that they not only detected signals with signal strength less than half the limit of shot noise, but also improved the accuracy to 1.5 times

the professor of Nanjing University said that this technology "certainly" can be used in quantum radar. However, a quantum scientist from Tsinghua University put this technology into practical use in a short time. The load sensor on the loading actuator ensures the accuracy of the loading force value; The spindle mechanism is driven by the control Electromechanical, and the ball screw runs along the x-axis. It is doubtful that the displacement is controlled by the high-precision displacement measuring mechanism. The quantum scientist, who asked for anonymity, said, "so far, I haven't heard of any practical application of weak measurement. Weak measurement is still measurement, which will inevitably change the state of the measurement object, thus limiting the application prospect of this technology."

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