At 1:40 on August 16, 2016, China successfully launched the world's first quantum science experimental satellite with the Long March II carrier rocket at the Jiuquan Satellite Launch Center.
From August 16th, the world’s first quantum science experimental satellite “Mozi†has been successfully launched for more than a month. In the theoretical sense, there is no fear of any monitoring of quantum communication. At the same time, whether it is truly safe or not, whether it is truly abandoned by European and American scientific research, has been heard all the time. The enthusiasm of the capital market has made many quantum concepts "crowd up."
From the collision of the view of the collision of the collision machine to the questioning of quantum communication, science welcomes the debate, but it is also true and false. On the 20th, Academician Pan Jianwei, Executive Vice President of the University of Science and Technology of China and Director of the Center for Excellence in Innovation in Quantum Information and Quantum Technology of the Chinese Academy of Sciences, interpret some of the issues of quantum communication when he participated in the “Dialogue Zhang Jiang†event in Shanghai.
About safety: What is the anti-interference ability? Is it stable enough?
After the quantum satellite was launched, there were articles on the Internet questioning whether this is an area that Europe and the United States do not play. If it is not good in Europe and America, can we do it well? In response to the international competition in the field of quantum communications, Pan Jianwei said that China is leading, and Europe and the United States are also stepping up their layout.
For example, the National Science and Technology Council (NSTC) recently published a report entitled "Developing Quantum Information Science: National Challenges and Opportunities." In May of this year, the European Commission announced at the European Quantum Conference in Amsterdam, the Netherlands, plans to launch a 1 billion euro quantum technology flagship program.
"In the past, our research and running years have been too long. Many people even think that good things have to be followed in Europe and America. This kind of feeling is very bad. This is why we named the Mozi number." Pan Jianwei said Mozi first experimented with light to propagate along a straight line, proposing the concept of particle and the prototype of Newton's law of inertia, so it is called "King Sheng". "We want to remind everyone by name that the Chinese can also do a good science. There are, there are, there will be more in the future."
For the security of quantum communication, there is a questioning voice on the network that if a piece of password information is eavesdropped, it will change the state of the quantum and expose the eavesdropping behavior. This password will be discarded; then, if this eavesdropping behavior persists The password has been discarded. Does it mean that the key can never be transmitted? Is absolute security actually sacrificing the stability of the transmission?
Faced with this question, Pan Jianwei responded that the state described above is to interfere with the communication process. If the interference is always going on, other communication modes cannot continue. Whether it is quantum communication or traditional communication, if you want it to be impossible, the cost of interference is the same.
"The anti-interference ability of traditional communication is not stronger than that of quantum communication, but usually people don't want to interfere with you. I can't wait for you to always say to steal more information." Pan Jianwei said, for example, if an eavesdropper controls the entire network. No matter whether it is classic communication or quantum communication, it cannot continue. But if you don't control the whole network, the principle of quantum uncertainty can make the transmission unconditionally safe.
In fact, many people are also worried that the current quantum communication is only the key is encrypted by quantum, and other information is still classic communication, can it be absolutely safe?
Pan Jianwei said that there have been numerous experiments to prove the principle of quantum entangled states. Two particles in an entangled state, if one of them is measured, the other particle outside the 100KM in the experimental data will also collaps. "Maybe we don't understand why there is a collapse now, but that doesn't prevent a useful attempt based on this."
Quantum encrypted transmission is one of the attempts. Pan Jianwei introduced that the usual communication of telephone, mail, etc., classic communication has been able to do very well, only need to complete the password through quantum encryption, to solve the security problem, without the need to transfer a variety of large-capacity information.
Quantum satellites that were magnetically tested at 812 (photo taken on December 2, 2014).
315Mhz Antenna Description:
The head straight rod antenna it is to 315 MHZ wireless digital/special meter reading communication system design of the antenna.The antenna standing wave ratio performance is good, small dimension, structure, easy installation, stable performance, has the very good anti vibration and aging.
Features:
Frequency range: 315Mhz
VSWR:<1.5
Input impedance:50Ω
Maximum power input: 10W
Gain: 3dBi
Polarization: Vertical polarization
Weight: 10g
Lead wire:no
Antenna color: black
Interface form: SMA
Picture show:
315mhz Antenna,315Mhz Rubber Antenna,Omni Directional Antenna,Short Rubber Antenna
Yetnorson Antenna Co., Ltd. , https://www.yetnorson.com