Experimental satellite launch world's first quantum will complete four tasks

1:40, the Jiuquan Satellite Launch Center, long second d carrier rocket successfully launched world's first quantum scientific experiment satellite

The Beijing News (reporters Jia Shiyu) 1:40 A.M. yesterday, at the Jiuquan Satellite Launch Center in China with a long second d carrier rocket successfully put the world's first quantum scientific experimental satellite "Mozi" is launched. This will make China the world's first satellite and quantum communication between ground, quantum communication and scientific experiments of construction of integrated vehicle and ground system.

4 surface quantum satellites and systems integration systems

Quantum satellite December 2011 project, is, Chinese Academy of Sciences space science pilot special first science experiment satellite one of, its main science target is with satellite platform, for star to high-speed quantum key key distribution experiment, and this based Shang for wide domain quantum key key network experiment, to in space quantum communications practical of aspects made major breakthrough; in space scale for quantum entanglement distribution and quantum stealth biography State experiment, carried out space scale quantum mechanics complete sex test of experiment research.

Engineering construction, including Nan shan, Delhi, is booming, Lijiang 4 quantum communication ground stations and Ali quantum teleportation experiment station, the ground application system, and together constitute the integrated vehicle and ground quantum science quantum satellite system.

Two-year life to complete four tasks

Pan Jianwei, Chief Scientist, academician of quantum satellite to the media, security based on the principles of quantum physics in quantum communication, integral to single photon and quantum States cannot be copied to ensure that the information is not hacking and uncrackable, in principle, ensure that the authentication, transmission encryption, and digital signatures, unconditionally secure, but fundamentally, permanent address information security issues.

According to Xinhua reported, quantum satellite will in two years of design life in the completed four task: star to high-speed quantum key key distribution experiment; wide domain quantum communications network experiment; satellite to apart 1200 km of station distribution entanglement of photon, in more Grand of scale Shang test was Einstein called "weird of" quantum entanglement phenomenon; also plans in "world roof" Tibet Ali and satellite Zhijian achieved quantum stealth biography State experiment.

Pan Jianwei said, "mo" after the launch, if desired, also plans to launch the next step "Mo-second" "Mo-third".

Focus

Quantum satellite experiment, to "secure" communications

In quantum world in the, a objects can while in multiple location, a only cat can in "died" and "live" of overlay State Shang; all objects are has "wave grain II as sex", is particles is wave; two a in "entanglement State" of particles, even apart distant also has "heart electric induction", a occurred changes, another will instantaneous occurred corresponding change......

Because with these different from the macroscopic quantum physics world of wonderful characteristics, constitute a cornerstone of quantum communication security. In quantum cryptography, quantum properties of an integral, not clones and uncertainty, so once you detect and avoid the eavesdropping must be sent.

"The traditional information security is dependent on complex algorithms, as long as the power is strong enough, no matter how complex the secret algorithm can be cracked. Can be absolutely secure quantum communication, is determined by the quantum nature of computing power also could not crack, it was revolutionary, but fundamentally, permanent address information security issues. "Quantum satellite's Chief Scientist, academician Pan Jianwei said.

In an international race in quantum communications, part of China. After years of efforts, China has been among the ranks of world-class research on quantum information, Metropolitan quantum communication technology in the world, completed city of Hefei, Jinan and other large-scale quantum communication networks, "the Beijing-Shanghai route" large scale optical quantum communication backbone network is nearing completion.

However, this is just the beginning. "Within the city, by fiber build Metro quantum communication network is the best solution. But to make long distance or global quantum communication, is not enough to rely solely on optical quantum communication technology. "Pan Jianwei said.

He explained that because photons of quantum information carriers travel up to 100 kilometers in the fiber signal reaches only about 1 ‰ after finally receiving optical quantum communication reach km magnitude is hard to break. But photons through the atmosphere can be maintained after about 80%, and then satellite relay, can be achieved on the ground thousands of kilometers apart, and even global coverage of the wide-area Quantum Cryptography.

In addition, the magic of quantum theory are repeated in the laboratory test, tested but never in space. Various strange phenomena of quantum theory are there in space? Quantum entanglement and teleportation can be extend to between the stars? These satellites are needed to verify.

According to Xinhua News Agency

Secrets

1 "four kinds of weapons" how to size small

At present, no country in the world of quantum science experiments into space, there is no experience to follow development of quantum satellite, the process is fraught with difficulties and challenges.

More than 600 with four kilos of quantum satellite payload: quantum entanglement quantum key communication machines, source, quantum entanglement, quantum control of the transmitter and processor, it will high Sun-synchronous orbit at a distance of 500 kilometers, about 90 minutes to orbit the Earth in a circle.

Meanwhile, in the scientific application of surface construction system, Center for quantum science experiments include 1 centers--Hefei; 4 station--South Mountain, Lijiang, delingha, Xinglong, quantum communication ground stations;-1 platform-Ali quantum teleportation experiment platform.

World of quantum science is very complex, of top test equipment requirements are unusually high. Pan Jianwei said satellite development process, the most difficult step is the payload, "overcome a lot of technical problems to win."

Source such as quantum entanglement, it is only the size of the set-top box, but critical, it can have entanglement, which is the source of quantum satellite in the air doing various experiments. Usual laboratory entanglement source volume is so great that researchers not only does miniaturization, and through a series of innovations making it meet the space requirements, at the international level was achieved for the first time.

To docked 2 stars such as "zhenjianduimaimang"

Quantum satellite launch, satellite and ground station is the interaction between plays.

Chinese scientists have used existing Astronomical Observatory station, in Lijiang, Yunnan, Xinjiang, Qinghai in delingha, Xinglong, Hebei construction of quantum communication ground stations. Quantum teleportation experiment from the ground to the satellite Photon, in order to avoid the effects of atmospheric turbulence, space quantum teleportation experiment station was built in an altitude of 5100 m Ali, Tibet.

Pan Jianwei said, "our experimental area of over 600,000 square kilometres, these formed the largest in human history ' quantum world integration lab. ”

However, to achieve interaction between heaven and Earth is not easy. Quantum Chief Designer of the satellite Zhu Zhencai said, "is a significant feature of quantum satellite to Delhi and Lijiang, or Delhi and Urumqi, two optical ground station at the same time achieving alignment, stars on the axis and the strict alignment of the optical axis of the telescope on the ground, with a metaphor that is zhenjianduimaimang. ”

Scientists say this calls for satellite alignment accuracy higher than ordinary satellite 10 times, experiments can be successfully expanded. The real problem is that this satellite will be in people's heads at a speed of approximately 8 km/s speed, ground stations only keep track of a few minutes at a time.

Quantum satellite engineering Executive Vice President Division and satellite commander Wang Jian-Yu said, to let through atmosphere Hou photon of "tip" still can on Shang station of "AWN", to guarantee quantum satellite and ground station between super high precision to aimed at, and capture and track information, research personnel from 2012 up on do has various experiment, including with hot air balloon to simulation space detector of vibration, and random mobile and height changes, with driving of vehicles Shang Mount of turntable to simulation satellite of speed and had.

According to Xinhua News Agency

Quantum experiment satellite

The four "arms"

Quantum key communication equipment

Quantum entanglement transmitter

Quantum entanglement resource

Experimental control and quantum processor

The four tasks

Star high-speed quantum key distribution experiment

Wide-area quantum communication network

Star quantum entanglement distribution experiment

Star experimental quantum teleportation

Experiments in three categories

Category: quantum key distribution between satellite and ground to achieve secure communication between heaven and Earth, if any between 22 and 4 ground stations can implement secure communications, enabling networking

Category II: equivalent to the laboratory moved to quantum space, spatial scale test of quantum theory

The third category: order of satellite and ground thousands of kilometers of quantum teleportation

(Editors: Liu Cheng UN649)
2016-08-17 01:49:12
The Beijing News

世界首颗量子实验卫星发射 将完成四大任务

　　昨日1时40分，酒泉卫星发射中心，长征二号丁运载火箭成功将世界首颗量子科学实验卫星发射升空

　　新京报讯 (记者贾世煜)昨日凌晨1点40分，中国在酒泉卫星发射中心用长征二号丁运载火箭成功将世界首颗量子科学实验卫星“墨子号”发射升空。这将使中国在世界上首次实现卫星和地面之间的量子通信，构建天地一体化的量子保密通信与科学实验体系。

　　4个地面系统与量子卫星构成一体化系统

　　量子卫星2011年12月立项，是中国科学院空间科学先导专项首批科学实验卫星之一，其主要科学目标是借助卫星平台，进行星地高速量子密钥分发实验，并在此基础上进行广域量子密钥网络实验，以期在空间量子通信实用化方面取得重大突破；在空间尺度进行量子纠缠分发和量子隐形传态实验，开展空间尺度量子力学完备性检验的实验研究。

　　工程还建设了包括南山、德令哈、兴隆、丽江4个量子通信地面站和阿里量子隐形传态实验站在内的地面科学应用系统，与量子卫星共同构成天地一体化量子科学实验系统。

　　两年设计寿命完成四大任务

　　量子卫星首席科学家潘建伟院士向媒体介绍，量子通信的安全性基于量子物理基本原理，单光子的不可分割性和量子态的不可复制性保证了信息的不可窃听和不可破解，从原理上确保身份认证、传输加密以及数字签名等的无条件安全，可从根本上、永久性解决信息安全问题。

　　据新华社报道，量子卫星将在两年的设计寿命中完成四大任务：星地高速量子密钥分发实验；广域量子通信网络实验；卫星向相距1200公里的地面站分发纠缠的光子，在更宏大的尺度上测试被爱因斯坦称为“诡异的”量子纠缠现象；还计划在“世界屋脊”西藏阿里和卫星之间实现量子隐形传态实验。

　　潘建伟表示，“墨子号”发射以后，如果效果达到预期，下一步还计划发射“墨子二号”“墨子三号”。

　　焦点

　　量子卫星将实验星地“安全”通信

　　在量子世界中，一个物体可以同时处在多个位置，一只猫可以处在“死”和“活”的叠加状态上；所有物体都具有“波粒二象性”，既是粒子也是波；两个处于“纠缠态”的粒子，即使相距遥远也具有“心电感应”，一个发生变化，另一个会瞬时发生相应改变……

　　正是由于量子具有这些不同于宏观物理世界的奇妙特性，才构成了量子通信安全的基石。在量子保密通信中，由于量子的不可分割、不可克隆和测不准的特性，所以一旦存在窃听就必然会被发送者察觉并规避。

　　“传统的信息安全都是依赖于复杂的算法，只要计算能力足够强大，再复杂的保密算法都能够被破解。量子通信能做到绝对安全，是由量子自身的特性所决定的，计算能力再强也破解不了，因此它是革命性的，可从根本上、永久性解决信息安全问题。”量子卫星首席科学家潘建伟院士说。

　　在量子通信的国际赛跑中，中国属于后来者。经过多年的努力，中国已经跻身于国际一流的量子信息研究行列，在城域量子通信技术方面也走在了世界前列，建设完成合肥、济南等规模化量子通信城域网，“京沪干线”大尺度光纤量子通信骨干网也即将竣工。

　　然而，这只是开始。“在城市范围内，通过光纤构建城域量子通信网络是最佳方案。但要实现远距离甚至全球量子通信，仅依靠光纤量子通信技术是远远不够的。”潘建伟说。

　　他解释说，因为量子的信息携带者光子在光纤里传播一百公里之后大约只有1‰的信号可以到达最后的接收站，所以光纤量子通信达到百公里量级就很难再突破。但光子穿透整个大气层后却可以保留80%左右，再利用卫星的中转，就可以实现地面上相距数千公里甚至覆盖全球的广域量子保密通信。

　　另外，量子理论的奇妙之处在实验室里被不断重复检验，但却从未在太空尺度验证过。量子理论的各种奇异现象在太空中是否还存在？量子纠缠和隐形传输是否可以延伸到星地之间？这些都需要卫星去验证。

　　据新华社

　　揭秘

　　1 “四种武器”如何块头变小

　　目前，国际上还没有一个国家将量子科学实验送入空间，量子卫星的研制没有任何经验可循，过程充满了困难和挑战。

　　600多公斤重的量子卫星带有四个有效载荷：量子密钥通信机、量子纠缠源、量子纠缠发射机、量子实验控制与处理机，它将在距离地面500公里高的太阳同步轨道，大约90分钟绕地球一圈。

　　同时，在地面建设了科学应用系统，包括1个中心——合肥量子科学实验中心；4个站——南山、德令哈、兴隆、丽江量子通信地面站；1个平台——阿里量子隐形传态实验平台。

　　天地量子科学实验非常复杂，对天地实验设备的要求也异乎寻常的高。潘建伟坦言，卫星研制过程中，最困难的环节就是有效载荷，“攻克了许多技术难题才拿下”。

　　比如量子纠缠源，它只有机顶盒的大小，作用却非常关键，它能够产生纠缠光，这是量子卫星在空中做各种实验的源头。平时实验室里纠缠源的体积非常巨大，研究人员不仅把它做到了小型化，还通过一系列的创新让它实现了满足空间环境要求，在国际上是首次实现。

　　2 星地对接如“针尖对麦芒”

　　量子卫星升空后，卫星与地面站之间的互动才是重头戏。

　　中国科学家利用已有的天文观测台站，在云南丽江、新疆乌鲁木齐、青海德令哈、河北兴隆建设了量子通信地面站。而量子隐形传态实验需要从地面向卫星发射光子，为了避免大气湍流的影响，空间量子隐形传态实验站建在了海拔5100米的西藏阿里。

　　潘建伟说：“我们的实验面积遍布60万平方公里，这形成了人类有史以来最大的‘天地一体化量子实验室’。”

　　然而，要做到天地互动并不容易。量子卫星总设计师朱振才说：“量子卫星的一个显著特点是要对德令哈与丽江，或德令哈与乌鲁木齐两个光学地面站同时实现对准，星上的光轴与地面望远镜光轴要严格对准，用一个形象的比喻就是针尖对麦芒。”

　　科学家说，这要求卫星的对准精度高于普通卫星的10倍，实验才能顺利展开。真正的问题在于，这颗卫星将在人们的头顶以约8公里/秒的速度飞驰，地面观测站每次只能持续跟踪几分钟。

　　量子卫星工程常务副总师兼卫星总指挥王建宇说，为了让穿越大气层后光子的“针尖”仍能对上接收站的“麦芒”，为了保证量子卫星与地面接收站间超高精度地瞄准、捕获和跟踪信息，科研人员从2012年起就做了各种实验，包括用热气球来模拟空间探测器的振动、随机移动和高度变化，用行驶的车辆上装载的转盘来模拟卫星的飞驰而过。

　　据新华社

　　量子实验卫星

　　四种“武器”

　　●量子密钥通信机

　　●量子纠缠发射机

　　●量子纠缠源

　　●量子实验控制与处理机

　　四大实验任务

　　●星地高速量子密钥分发实验

　　●广域量子通信网络实验

　　●星地量子纠缠分发实验

　　●地星量子隐形传态实验

　　实验分三类

　　第一类：进行卫星和地面之间的量子密钥分发，实现天地之间的安全通信，如果4个地面站任何两两之间都可以实现安全的通信，即可实现组网

　　第二类：相当于把量子实验室搬到太空，在空间尺度检验量子理论

　　第三类：实现卫星和地面千公里量级的量子态隐形传输

(责任编辑：刘盛钱 UN649)
2016-08-17 01:49:12
新京报