HEFEI, July 25 -- Chinese scientists have made another breakthrough in quantum communication, demonstrating long-distance free-space quantum key distribution during daylight.
In the past, long-distance free-space quantum communication experiments could only be performed at night, because sunlight, or sunlight noise, prohibits quantum communication in transmission under conditions of high channel loss over long distances.
Therefore, the world's first quantum satellite, Quantum Experiments at Space Scale (QUESS) launched by China in 2016, can only send photons at night, and it takes at least three days for QUESS to cover all ground stations around the Earth.
A team from the University of Science and Technology of China led by Pan Jianwei, an academician with the Chinese Academy of Sciences, has overcome the sunlight noise issue and demonstrated free-space quantum key distribution over 53 km during the day.
Pan's team chose a wavelength of 1,550 nanometers and developed free-space single-mode fibre-coupling technology and ultra-low-noise upconversion single-photon detectors to achieve the daytime distribution.
The new technology was announced on Monday in the journal of Nature Photonics.
"Our experiment has proved the feasibility of satellite-based quantum in daylight, and laid a foundation for a satellite-constellation-based global quantum network," said Pan.
Quantum communication is ultra-secure as a quantum photon can neither be separated nor duplicated. Accordingly, it is impossible to wiretap, intercept or crack information it transmits.
China is striving to set up the first-ever global quantum communication network by around 2030, through linking a satellite constellation consisting of dozens of quantum satellites and ground-based quantum communication networks.
精美散文:守护自己的天使
如果生命可以重来(双语)
献给女性:如果生命可以重来
浪漫英文情书精选:Good Morning早上好
精选英语美文阅读:假如生活欺骗了你
人生哲理:年轻无悔 别停下追寻梦想的脚步
英语美文欣赏:A beautiful song
生命可以是一座玫瑰花园
精选英语美文阅读:A Friend's Prayer 朋友的祈祷
26个英文字母蕴含的人生哲理
英语晨读:忘忧树
浪漫英文情书精选:The Best Surprise最好的惊喜
精选英语美文阅读:哪有一株忘忧草? (双语)
英语美文:Keep on Singing
精选英语美文阅读:朋友的祈祷
美文:爱的奇迹
精选英语美文阅读:被忽略的爱 Helpless love
双语散文: Optimism and Pessimistic
爱情英语十句
双语美文:I Wish I Could believe
最美的英文情诗:请允许我成为你的夏季
英语美文:A Psalm of Life 人生礼颂
精选英语散文欣赏:微笑挽救生命
浪漫英文情书精选:Need You With Me需要你爱我
精美散文:27岁的人生
英文《小王子》温情语录
浪漫英文情书精选:Keep You Forever永远温存着你
态度决定一切 Attitude Is Everything
精选英语美文阅读:你见或者不见我(中英对照)
精选英语美文阅读:饶孟侃《呼唤》
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |