研究成果发表在2007年12月19日出版的国际权威物理学最权威的期刊《 Physical Review Letters》上,标志着我国光学量子计算机研究达到了国际领先水平。

November 2007, to be published in Physical Review Letters

Demonstration of a compiled version of Shor's quantum factoring algorithm using photonic qubits

Chao-Yang Lu, Daniel E. Browne, Tao Yang, and Jian-Wei Pan

We report an experimental demonstration of a complied version of Shor's algorithm using four photonic qubits. We choose the simplest instance of this algorithm, that is, factorization of $N=15$ in the case that the period $r=2$ and exploit a simplified linear optical network to coherently implement the quantum circuits of the modular exponential execution and semi-classical quantum Fourier transformation. During this computation, genuine multiparticle entanglement is observed which well supports its quantum nature. This experiment represents an essential step toward full realization of Shor's algorithm and scalable linear optics quantum computation.

2007 The American Physical Society.

中国科技大学的这篇prl 似乎很有分量。两个月前,这篇论文还仅仅是预印本的时候,《新科学家》(new scientist)就报道了


Quantum threat to our secret data

* 13 September 2007

* Saswato Das

* Magazine issue 2621

IT MIGHT seem like an esoteric achievement of interest to only a handful of computer scientists, but the advent of quantum computers that can run a routine called Shor's algorithm could have profound consequences. It means the most dangerous threat posed by quantum computing - the ability to break the codes that protect our banking, business and e-commerce data - is now a step nearer reality.

Adding to the worry is the fact that this feat has been performed by not one but two research groups, independently of each other. One team is led by Andrew White at the University of Queensland in Brisbane, Australia, and the other by Chao-Yang Lu (USTC的,第一作者;潘建伟是通信作者) of the University of Science and Technology of China, in Hefei. Both groups have built rudimentary laser-based quantum

computers that can implement Shor's algorithm - a mathematical routine capable of defeating today's most common encryption ...


http://www.innovations-report.de ... /bericht-99247.html

A quantum computer breakthrough and dark matter stars


Highlights in this issue: A quantum computer breakthrough and dark matter stars.


Quantum Computer Breakthrough

Chao-Yang Lu, Daniel E. Browne, Tao Yang, and Jian-Wei Pan

Physical Review Letters (forthcoming) &

B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James , A. Gilchrist, and A. G. White

Physical Review Letters (forthcoming)

Two research groups have independently managed to experimentally solve a mathematical problem with light-based quantum computers. The simultaneous achievements appear to be the first experimental demonstrations of true (though rudimentary) quantum mechanical computations. Both groups manipulated quantum mechanically entangled photons to calculate the prime factors of the number 15.

Although the physicists could have gotten the answer to the problem much more easily by querying an average elementary school child, the method both groups used involved a quantum mechanical approach commonly known as Shor's algorithm. Previous theoretical work has shown that the algorithm could potentially crack cryptographic codes that are practically unbreakable with non-quantum mechanical (classical) computers.

While there's no great need to factor numbers as small as 15, the research demonstrates that quantum computation is feasible with existing technology and could in principle be scaled up to tackle problems that would take longer than the age of the universe to solve with any classical computer, but would require only minutes on a quantum computer.

In addition to factoring large numbers and solving other challenging mathematical problems, quantum computers based on the work of these two groups could help model quantum mechanical problems in physics and chemistry (sehttp://xxx.lanl.gov/ftp/arxiv/papers/0710/0710.0278.pdf for an example of a quantum simulator experiment by C.-Y. Lu et al.), and lead to ultra high speed searching algorithms.

Chao-Yang Lu (USTC的,第一作者;潘建伟是通信作者)and his group are currently expanding on their work by trying to manipulate larger numbers of quantum bits. In the long run, they plan to add quantum memory to their quantum computers, which could further increase the number of photons they can control. In addition, because the loss of photons is a huge problem for light-based quantum computation, they are working on some basic quantum codes that can protect the quantum information from photon loss error. These sorts of issues are crucial in the effort to scale up photonic quantum computation. - JR



Both groups have built rudimentary laser-based quantum

computers that can implement Shor's algorithm - a mathematical routine capable of defeating today's most common encryption .



九月,该小组利用光子“超纠缠簇态”演示了单向量子计算的物理过程,实现了量子搜索算法,论文发表在《Physical Review Letters》上。

最近,该小组又在国际上首次利用光量子计算机实现了Shor量子分解算法,研究成果发表在12月19日出版的国际最权威物理学期刊《Physical Review Letters》上,标志着我国光学量子计算研究达到了国际领先水平。


2007年3月,潘建伟教授应邀和美国UIUC大学教授P. Kwiat,NIST教授D. Wineland,维也纳大学教授A. Zeilinger一起在美国物理年会新闻发布会上介绍了量子信息的最新进展。





人民日报网络版8月21日讯 近日,世界上最先进的量子计算机在IBM阿蒙德(Almaden)研究中心研制成功。科学家宣称量子计算机能够解决传统计算机难以完成的计算问题。

Isaac L. Chuang是研究小组领导人,领导着来自IBM研究院、斯坦福大学以及Calgary大学的科学家,他说:“预计2020年将是量子计算机的时代,摩尔定律不再实用,集成电路将由分子和原子直接构成。事实上,构成量子计算机的基本元素就是分子和原子。”





“次序查找”问题又可通过以下方式描述:在一个有许多房间的屋子里,随机放置着相同数量的单向通道,一些通道能够自己构成回路,返回启始点。由此可以判定,在某种情况下,一个人穿过一定数量的房间和通道可以回到启始房间。这个问题是以最少次数的查询模式,计算出一个人返回启始房间前所必须通过的最少通道数。IBM研制出的5量子位计算机能够用一步计算就解决各种问题,而传统计算机要依照不同情况分四步计算得出结果。这项最新成果证实了早些时候由加拿大Calgary大学Richard Cleve教授做出的预测。




8月16日,在斯坦福大学召开的Hot Chips 2000的会议上,Chuang向人们展示了这项最新研究成果(这个会议是由美国电气工程师协会(IEEE)计算机分会组织的)。Chuang的合作伙伴有IBM Almaden研究中心的Grgory Breyta和Costantino S. Yannoni,斯坦福大学研究生Lieven M. K. Vandersypen和Matthias Steffen,以及Calgary大学的计算机理论学家Richard Cleve。研究小组还就试验成果向著名刊物“科学”杂志和“物理展望”杂志提交了一份技术报告。


当量子计算机理论在七、八十年代被第一次提出时(其理论学家有加里福尼亚技术研究院的Richard Feynmann,Argonne国家实验室的Paul Benioff,牛津大学的David Deutsch,以及IBM 华盛顿研究中心的Charles Bennett),许多科学家对能否真正制造出这样的机器持怀疑态度。但到了1994年,AT&T研究院的Peter Shor提出了一种能比传统计算机运算速度快上指数幂倍数的量子算法,这个算法强大到足以解开著名的公开秘钥加密算法中的私用秘钥。Shor的算法为量子计算机的发展开辟了道路。从此,世界众多研究小组加入该研究行列,在量子计算机研究领域取得的重大进步络绎不绝。



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